64 



nearly median. In no case is a distinct communication with the ex- 

 terior present, though contact with the skin is frequently very intimate. 

 This condition, and perhaps to some extent also the small number of 

 gonads, is no doubt due to immaturity of the organs at the season 

 (Jan. 1894) when the specimens were taken. 



In the two undoubtedly bisexual individuals the anterior part of 

 the body is male, the posterior female. This agrees with what K e fer- 

 st ein found in T. hermaphroditica\ while in T. Kef er s teinii and Geone- 

 mertes palaensis the male and female organs are more or less intermixed. 

 One individual is chiefly male, possessing six distinct testes, and three 

 distinct ovaries; the other mainly female, with a single well marked 

 anterior testis immediately posterior to the end of the short proboscis 

 sheath, and the remaining gonads, except a few very immature ones of 

 questionable identity, female. 



The testes are more or less flattened turnip-shaped bodies, with a 

 usually very indistinct enveloping capsule. Cell boundaries are not 

 obvious in the cortical layer of protoplasm , in which are embedded 

 many large distinct nuclei with finely divided chromatin, though there 

 is occassionally present a nucleus with a single spherical nucleolus, 

 which so closly resemble the nuclei of the female gonoblasts that one 

 is led to infer for them a similar destiny. The nuclei of the central 

 portion of the protoplasmic mass exhibit a few very large nuclei in 

 various stages of sub-division and transformation into spermatozoa, 

 the most advanced stages of which are rather coarse deeply staining 

 threads, one end of which often shows knob-like enlargments. These 

 form irregular tangled skeins which wind around the 

 complete nuclei and penetrate the surrounding proto- 

 plasm, on the surface of which they often lie. Sac- 

 like spermatic receptacles are present in connection 

 with at least some of the testes. Fig. 1 represents the 

 outline of the testes and the nuclear appearances of a 

 typical section magnified 500 diams. 



The ovaries are more nearly spherical in shape, 

 and like the testes have usually the appearance of solid 

 masses of protoplasm, through the cortical layer is 

 more definite, and in a few cases is in part separated 

 by a distinct space from the maturing ova , which 

 occupy a central position. The peripheral nuclei are 

 much larger than the corresponding ones of the male organ, and lie 

 nearer together in an apparently undivided finely granular protoplasm. 

 Each possesses a single (or when apparently dividing, two) perfectly 

 spherical, clear, rather deeply stained nucleolus, in which there is fre- 



