460 GEOLOGICAL SUEVEY OF THE TEREITORIES. 



nently developed, serving as a rudder organ; after the subsequent 

 moults this organ becomes gradually shorter, less movable, bent down, 

 loses its bristled margin, and in the females is transformed into two 

 small, scarcely movable, tongae-like bent processes, while in the males 

 the same develops itself into disproportionately large claspers with 

 broad lobes, functionating as a catching and clasping apparatus. These 

 robust claspers, bent downwards and backwards, betray the male sex, 

 as above stated, in the earlier stages by an incipient swelling of the said 

 rudder organs, while the same, after their hystolytic degeneration, re- 

 main small in the females. In this way it was easy for me early to dis- 

 tinguish the males from the females and, significant for my experiments, 

 to keep them apart. 



Tlie growth and prosperity of the carefully-separated sexes proceeded 

 well in various jars with artificial sea water, and pains were also taken 

 to add only boiled Utah mud to prevent any Artemia eggs from hatch- 

 ing. Without this precaution I would eventually have received younger 

 broods ot different sexes together with the older ones, already kept 

 apart, which would have interfered with my experiments, in which 

 latter the utmost certainty was required to prevent the meeting of the 

 two sexes before the setting in of concupiscense. Having raised a large 

 number of carefull.y- watched virgin individuals in the above mentioned 

 manner, I waited the period of contjupiscence in one-half of their num- 

 ber without giving them occasion to come in contact with any males, 

 while the other half of virgins I placed together with a number of ma- 

 tured male individuals for the purpose of getting fertilized by them. I 

 succeeded in this, since the males very earlj^, as already stated, betrayed 

 their future sex and were vigorously grown up, and gave repeated indi- 

 cations of sexual desires. They manifested the latter in their ])ugna- 

 eious behavior, embracing themselves with their powerful claspers in 

 such a manner as if they would jierform copulation; many of them 

 clasped other males, no matter how they struggled against it, and with 

 such a violent fervor that they, as may be assumed, applied the claspers 

 on almost every part of their body. Such couples remained entangled 

 for several days, swimming around in the most unnatural positions. 



The testicles, filled with whitish zoosj^erms, presented themselves to 

 the naked eye through the translucent body. I selected the most vigor- 

 ous individuals, placing them in a jar together with boiled-up Utah mud 

 and a number of virgin Artemise, and had then very soon the pleasure 

 to see tbat they did not refuse the ardent embraces of the males, the 

 females making no efitbrts to free themselves of their burden. The 

 male with its claspers embraces the i)ostabdomen of the female from 

 the back, which region appears swollen by the ovisac. In this way both 

 individuals, bearing their abdomens parallel above each other, swim 

 about as if animated with but one will. From time to time such a 

 couple swims along the surface of the mud, turns around its longitudinal 

 axis, dorsal side up, thus whirling up the loose mud for the i)urpose of 

 obtaining food. Occasionally the male, utilizing the embrace of the 

 female, bends its postabdomen around for the purpose of inserting its 

 two protrusile cylindrical copulative organs into the female genital 

 orifice, whereby the closest contact with the female, as well as an afflux 

 of spermatic particles, was effected.- 



The actual process of copulation, as closely observed by me, was 

 interrupted after shorter or longer intervals, but in incessantly long- 

 continued embraces it was often repeated. One of these couples hung 

 together for three days. After coi)ulation ensued, I transferred those 

 females which were abandoned by their males and which females I re- 



