448 SUMMARY OF CURRENT RESEARCHES RELATING TO 



chromaphil secretion is not found in the young glands, nor does it ever 

 occur in cutaneous glands in other parts of the body. As the gland 

 grows older without being used, the chromaphil secretion diffuses into 

 the central part of the gland, so that the entire venom stains yellow with 

 chromate solutions. The homogeneous liquid is the first secretion to 

 reach the skin surface when the gland discharges in response to a 

 stimulus, probably because it is less viscous than the granular secretion, 

 and its appearance is followed by the ejection of the first or granular 

 emulsion in the centre of the gland. In this way the adrenalin com- 

 ponent of the gland-venom is the first poison to reach the mucous 

 membranes of an attacking animal. 



The adrenalin-content of the venom is not secreted as such by the 

 glandular epithelium, since at no time in their history do the epithelial 

 cells show any yellowing after treatment with chromate solutions, nor 

 does the poison-sac contain chromaphil material until long after the 

 disappearance of all epithelial elements. The adrenalin is probably the 

 result of a change produced in a mother-substance, which is very likely 

 an amino-acid, as Guggenheim first suggested, through the action of the 

 naked nuclei of the old epithelial cells, which remain attached to the 

 inner surface of the wall of the poison-sac. Analogous processes occur- 

 ring elsewhere in nature suggest that the change in question may be a 

 process of decarboylization, which results in the formation of this 

 aromatic amin base from a corresponding acid. 



There is no clue to the origin of the hypothetical amino-acid, but 

 such an acid might readily be a result of the breaking down of the 

 cellular elements of the gland, since many amino-acids are derivatives of 

 protein destruction. The granular secretion would appear to be formed 

 directly in the cytoplasm of the gland-cells during their most active 

 period of swelling and breaking down. The chromaffin organs of the 

 body (adrenal, medulla, etc.) do not appear to influence or be influenced 

 by the presence of the cutaneous depots of adrenalin. 



As regards Living Matter.* — B. Verigo discusses the difficulties 

 in the way of forming clear conceptions of living matter. Physiologists 

 find no essential difference between frog's muscle and horse's muscle ; 

 but grafting experiments point to marked specificity in the living matter 

 of different types. On the one hand, there is the fact of division of 

 labour among the differentiated cells of the body ; on the other hand, 

 many experiments show that underlying the differentiation in one 

 organism there is a great similarity in essential features and capacities. 

 Physiologists speak of the instabihty of living matter, which is con- 

 tinually undergoing metabolism •; biologists studying heredity are wont 

 to emphasize the stability of living matter. Biologists are dealing 

 mainly with idioplasm, living matter of the first order, active during 

 development, giving place to differentiated cytoplasm, but conserved in 

 the nucleus and in a small quantity of cytoplasm around the nucleus. 

 Physiologists are dealing mainly with living matter of the second order, 

 differentiated cytoplasm. 



* C.R. Soc. Biol. Paris, Ixxix. (1916) pp. 1155-6, 



