338 



V. On the precocious Development of the Testis, and 

 the Absence of Eleoblast, in young Chain Individuals 

 of Salpa cylindrica. 

 It is said that the eggs borne by the individuals of the stolon 

 in the Salpce mature, are fertilized and proceed a certain distance in 

 their development, before the sperm cells in the testis of the same 

 individual ripen ^). Those who regard the egg as an integral part of 

 the chain individual would say, then, that we have in the Salpas an 

 example of protogynous hermaphroditism. In my study of older 

 stolons of S. cylindrica, still attached to the parent, I have found 

 conditions not reconcilable with this statement. Fig. 9 is a drawing of 



Fig 9. Individual detached from a stolon of S. cylindrica. (Actual length about 

 1^4 mm.) 



a atrial opening ; cf ciliated funnel ; gg ganglion ; i intestine ; m mouth ; nc nucleus \ 

 oe oesophagus ; t testis. 



an individual detached from a well developed stolon of S. cylindrica. 

 The individual zoöids of the stolon are about I'^/j mm long. At the 

 point (t) is seen the very large bilobed testis. At first glance it seems 



S. runcinata, S. cordiformis or S. scutigera, to dissect out the large, pig- 

 mented, dorsal eye, which lies just beneath the ectoderm, and to leave 

 intact the ganglion with the smaller uupigmented eyes. A comparison 

 of such individuals with normal ones, as regards their relation to light 

 stimulation, might give interesting results in line with the considerations 

 here proposed. 



1) See KoEscHELT and Heidf.b, Lehrbuch der vergleich. Entwickelungs- 

 geschichte der wirbellosen Tiere, p. 1333 and 1334. 



