Chondrin is a bluish-white gelatin-like substance, being a protein–carbohydrate complex and can be obtained by boiling cartilage in water. The cartilage is a connective tissue that contains cells embedded in a matrix of chondrin. Chondrin is made up of two proteins 

• chondroalbunoid
  • not only is there no wikipedia page, although it looks like there should be, there is no dictionary definition. there are a few mentions elsewhere on the internet, many of them repeating the same sentence seen here or something very similar. and that’s just weird even for obsolete and maybe even misspelled terms but that’s all on that for now. i’m going to assume albunoid involves albumin even though when I look that up I get some disturbing links to resident evil, albinism and slangy terms for white people in general. we are in no mood for that so moving along….
• chondromucoid
  • a white amorphous substance obtainable from the matrix of cartilage and consisting of a protein that resembles gelatin and is combined with chondroitin sulfate
    • https://www.merriam-webster.com/medical/chondromucoid

See also

• Chondroitin

External links

Charles Darwin – Insectivorous Plants Page 56 (added below minus the milk section)

Categories: 

• Animal products
• Edible thickening agents
• Proteins

I therefore wished to compare its action with that of pure gelatine. Solutions of one part of both substances to 218 of water were made; and half-minim drops (.0296 ml.) were placed on the discs of eight leaves, so that each received 1/480 of a grain, or .135 mg. The four with the isinglass were much more strongly inflected than the other four. I conclude therefore that isinglass contains some, though perhaps very little, soluble albuminous matter. As soon as these eight leaves re-expanded, they were given bits of roast meat, and in some hours all became greatly inflected; again showing how much more meat excites Drosera than does gelatine or isinglass. This is an interesting fact, as it is well known that gelatine by itself has little power of nourishing animals.*

Chondrin.–This was sent me by Dr. Moore in a gelatinous state. Some was slowly dried, and a small chip was placed on a leaf, and a much larger chip on a second leaf. The first was liquefied in a day; the larger piece was much swollen and softened, but was not completely liquefied until the third day. The undried jelly was next tried, and as a control experiment small cubes were left in water for four days and retained their angles. Cubes of the same size were placed on two leaves, and larger cubes on two other leaves. The tentacles and laminae of the latter were closely inflected after 22 hrs., but those of the two leaves with the smaller cubes only to a moderate degree. The jelly on all four was by this time liquefied, and rendered very acid. The glands were blackened from the aggregation of their protoplasmic contents. In 46 hrs. from the time when the jelly was given, the leaves had almost re-expanded, and completely so after 70 hrs.; and now only a little slightly adhesive fluid was left unabsorbed on their discs.

* Dr. Lauder Brunton gives in the ‘Medical Record,’ January 1873, p. 36, an account of Voit’s view of the indirect part which gelatine plays in nutrition. [page 113]

One part of chondrin jelly was dissolved in 218 parts of boiling water, and half-minim drops were given to four leaves; so that each received about 1/480 of a grain (.135 mg.) of the jelly; and, of course, much less of dry chondrin. This acted most powerfully, for after only 3 hrs. 30 m. all four leaves were strongly inflected. Three of them began to re-expand after 24 hrs., and in 48 hrs. were completely open; but the fourth had only partially re-expanded. All the liquefied chondrin was by this time absorbed. Hence a solution of chondrin seems to act far more quickly and energetically than pure gelatine or isinglass; but I am assured by good authorities that it is most difficult, or impossible, to know whether chondrin is pure, and if it contained any albuminous compound, this would have produced the above effects. Nevertheless, I have thought these facts worth giving, as there is so much doubt on the nutritious value of gelatine; and Dr. Lauder Brunton does not know of any experiments with respect to animals on the relative value of gelatine and chondrin.

INSECTIVOROUS PLANTS BY CHARLES DARWIN, M.A., F.R.S. ETC. WITH ILLUSTRATIONS.

CONTENTS.

CHAPTER I.

DROSERA ROTUNDIFOLIA, OR THE COMMON SUN-DEW.

Number of insects captured–Description of the leaves and their appendages or tentacles– Preliminary sketch of the action of the various parts, and of the manner in which insects are captured–Duration of the inflection of the tentacles–Nature of the secretion–Manner in which insects are carried to the centre of the leaf–Evidence that the glands have the power of absorption–Small size of the roots…Pages 1-18

CHAPTER II.

THE MOVEMENTS OF THE TENTACLES FROM THE CONTACT OF SOLID BODIES.

Inflection of the exterior tentacles owing to the glands of the disc being excited by repeated touches, or by objects left in contact with them–Difference in the action of bodies yielding and not yielding soluble nitrogenous matter–Inflection of the exterior tentacles directly caused by objects left in contact with their glands–Periods of commencing inflection and of subsequent re-expansion–Extreme minuteness of the particles causing inflection–Action under water–Inflection of the exterior tentacles when their glands are excited by repeated touches–Falling drops of water do not cause inflection…19-37 [page vi.]

CHAPTER III.

AGGREGATION OF THE PROTOPLASM WITHIN THE CELLS OF THE TENTACLES.

Nature of the contents of the cells before aggregation–Various causes which excite aggregation–The process commences within the glands and travels down the tentacles– Description of the aggregated masses and of their spontaneous movements–Currents of protoplasm along the walls of the cells–Action of carbonate of ammonia–The granules in the protoplasm which flows along the walls coalesce with the central masses–Minuteness of the quantity of carbonate of ammonia causing aggregation–Action of other salts of ammonia–Of other substances, organic fluids, &c.–Of water–Of heat–Redissolution of the aggregated masses–Proximate causes of the aggregation of the protoplasm–Summary and concluding remarks–Supplementary observations on aggregation in the roots of plants…Pages 38-65

CHAPTER IV.

THE EFFECTS OF HEAT ON THE LEAVES.

Nature of the experiments–Effects of boiling water–Warm water causes rapid inflection– Water at a higher temperature does not cause immediate inflection, but does not kill the leaves, as shown by their subsequent re-expansion and by the aggregation of the protoplasm– A still higher temperature kills the leaves and coagulates the albuminous contents of the glands…66-75

CHAPTER V.

THE EFFECTS OF NON-NITROGENOUS AND NITROGENOUS ORGANIC FLUIDS ON THE LEAVES.

Non-nitrogenous fluids–Solutions of gum arabic–Sugar–Starch–Diluted alcohol–Olive oil– Infusion and decoction of tea–Nitrogenous fluids–Milk–Urine–Liquid albumen–Infusion of raw meat–Impure mucus–Saliva–Solution of isinglass–Difference in the action of these two sets of fluids–Decoction of green peas–Decoction and infusion of cabbage–Decoction of grass leaves…76-84 [page vii.]

CHAPTER VI.

THE DIGESTIVE POWER OF THE SECRETION OF DROSERA.

The secretion rendered acid by the direct and indirect excitement of the glands–Nature of the acid–Digestible substances–Albumen, its digestion arrested by alkalies, recommences by the addition of an acid–Meat–Fibrin–Syntonin–Areolar tissue–Cartilage–Fibro-cartilage– Bone–Enamel and dentine–Phosphate of lime–Fibrous basis of bone–Gelatine–Chondrin– Milk, casein and cheese–Gluten–Legumin–Pollen–Globulin–Haematin–Indigestible substances–Epidermic productions–Fibro-elastic tissue–Mucin–Pepsin–Urea–Chitine– Cellulose–Gun-cotton–Chlorophyll–Fat and oil–Starch–Action of the secretion on living seeds–Summary and concluding remarks…Pages 85-135

CHAPTER VII.

THE EFFECTS OF SALTS OF AMMONIA.

Manner of performing the experiments–Action of distilled water in comparison with the solutions–Carbonate of ammonia, absorbed by the roots–The vapour absorbed by the glands- -Drops on the disc–Minute drops applied to separate glands–Leaves immersed in weak solutions–Minuteness of the doses which induce aggregation of the protoplasm–Nitrate of ammonia, analogous experiments with–Phosphate of ammonia, analogous experiments with- -Other salts of ammonia–Summary and concluding remarks on the action of salts of ammonia…136-173