BIOCHEMISTRY OF THE SEXUAL ORGANS 295 



In Helm's l view this lipochrome is not formed in the ovary but in 

 some other organ of the body, and passes at the period of ovulation 

 into the blood, which carries it to the ovaries. 



The same author, together with Abelous, 2 has proved the existence 

 of some ferments in watery and glycerine extracts of the eggs of 

 various Crustacea. A diastatic, a tryptic, and an inverting ferment 

 were found. They are stated to increase in strength during the 

 maturation of the ovum. 



Heim's observations on the appearance of a lutein in the blood of 

 the female during ovulation have acquired great significance from 

 the remarkable work of Geoffrey Smith 3 on crustaceans. In these 

 animals the " liver," which corresponds to almost the entire digestive 

 and metabolic apparatus of the higher animals, varies greatly in its 

 composition according to the condition of the crab in respect to two 

 functions reproduction and moulting. The quantitative variations, 

 which are reflected also in the composition of the blood, refer to the 

 amounts of glycogen and of fat present. In addition there are 

 qualitative changes in the nature of the lipochrome circulating in the 

 blood. Thus in male crabs (Carcinus mcenas) the glycogen and fat- 

 content of the liver is low immediately after moulting and the blood 

 is colourless and carries little fat. In the intermediate period 

 bet\veen two moults there is an increase in the glycogen and fat- 

 content of the liver. The blood is pink owing to the presence of the 

 red pigment tetronerythrin, which is deposited in the shell. The fat- 

 content of the blood, however, remains low (0'08 per cent.). 



In female crabs which are maturing their ovaries preparatory to 

 breeding, the liver is rich in fat and contains a fair amount of 

 glycogen. The blood is very rich in fat (0*2 per cent.). But its most 

 striking feature is its light yellow colour, due to the presence of a 

 yellow lutein which is being formed in the liver and carried by the 

 blood to the ovaries, where it is deposited in the yolk of the eggs. 

 After the eggs have been shed the blood becomes again colourless. 

 The resulting secondary sexual characters of the male are, therefore, 

 that the external colour is redder than that of the female, and. that 

 the male is larger. 



If now crabs of both sexes are infected with Sacculina they cease 

 to grow, moult or reproduce, but they all present the same condition, 

 namely that of a female crab with mature ovaries, and that occurs 

 even with male crabs. The glycogen-content is low, the fat-content 



1 Helm, Etudes sur le Sang des Crustaces, Paris, 1892. 



- Abelous and Heim, " Sur les Ferments des (Eufs des Crustaces," Compt. 

 Rend. Soc. Bid., vol. xliii., 1891, p. 273. 



3 Geoffrey Smith, " The Effect of Reproductive Cycle on Glycogen and Fat 

 Metabolism in Crustacea," British Assoc., 1913, p. 670. See also British Assoc., 

 1910, p. 635 ; 1911, p. 414. 



