354 SUMMARY OF CURRENT RESEARCHES RELATING TO 



In animals between 12 and 26 mm., the width of the body, the 

 interval between anterior and posterior fins, the interval from posterior 

 fin to seminal vesicle, and the length of the ovary, increase more, rapidly 

 than the animal increases in size, while the ventral ganglion increases 

 less rapidly than the animal does. Therefore, the ratio between these 

 various measurements and length of animal is of certain specific value 

 only for animals of definite lengths. 



The number of anterior and posterior teeth and seizing jaws increases 

 as the animal grows larger, the rate of increase being greatest in the 

 posterior teeth and smallest in the seizing jaws. Therefore the specific 

 value in number of these structures depends not only on the extremes of 

 variation, but, quite as definitely, on the amount of variation in the 

 rates of increase. 



Nematohelminthes. 



New Species of Tropidocerca.* — L. G. Seurat describes Tropidocerca 

 nouvell sp. n. from the viscera of a stilt (Himantopus himantopus). The 

 median part of the female is extraordinarily swollen and pyriform and 

 of a carmine colour. The ovijector is of the type of T. inermis. The 

 male is marked by the possession of a single delicate spicule. 



Platyhelminth.es. 



Two Ceylonese Temnocephalid8e.+ — L. Plate describes Caridinicola 

 indica Annandale from Garidina simoni and Monodiscus parvus sp. n. 

 from the same prawn. Both forms especially frequent the gill-chamber, 

 but they creep about on other parts of the body. A third symbiotic 

 form, a Rotifer, also occurs in abundance, especially about the mouth, 

 and is eaten by the Temnocephalids. It appears that Caridinicola indica 

 is a protandrous hermaphrodite. 



Ichthyotsenia filicollis.i — F. J. Meggitt describes this tapeworm 

 from the stickleback (Gasterosteus aculeatus), giving an account of the 

 general and minute structure. Evidence is given that the intermediate 

 host is Cyclops varius, successful experiments having been made in infect- 

 ing the Cyclops with the tapeworm egg and the stickleback with the larva 

 in the Cyclops. The fertilized ovum divides into a vitelline cell crowded 

 with yolk-granules and a " Keimzelle " with nucleus and nucleolus. The 

 " Keimzelle ■" divides into two and each of these into two again, four 

 cells of equal size being formed. In subsequent divisions the nuclei 

 are of two sizes, and the cells containing the larger nuclei surround the 

 others. A split appears between the two, and this gradually widens 

 until the first cells form a definite coat — the second oncospheric mem- 

 brane — around the smaller ones. The vitelline cell does not last long, 

 but degenerates into a mass of yolk-follicles. 



-^- v 



* C.R. Soc. Biol. Paris, lxxvi. (1914) pp. 778-81 (8 figs.), 

 t Jen. Zeitschr. Naturw., li. (1914) pp. 707-22 (2 pis.). 

 | Proc. Zool. Soc, 1914, pp. 113-38 (4 pis. and 5 figs.). 



