The Sexual Conditions of Myzostoma glabrum (F. S. Leuckart;. 315 



passages may, I tbink, be takeu as completely justifying an accep- 

 tation of the »perfectly imisexual« 1 or dicecious nature of il/, inflator 

 and M. murrmji^ in other words, of the presence of purely difficious 

 species withiu the geniis, and of a conclusion as to the existenee 

 of wbat it »pleases« me to cali »complemental« or dwarf males. 



Wben I established the existenee of complemental males 2 in 

 M. glabrum — as the facts forced me, not as it »pleased« me to 

 do — this action was taken ou two grounds. From my investigations 

 it invariably resulted that these were true males, and tbey were 

 always found to occupy a typieal position upon and near the anterior 

 end of the hermaphrodite. Anytbing found elsewhere was never a 

 true dorsicole, and the two characters must be taken together in any 

 attempt to overturn the conclusion. 



I hold, until the contrary has been proved, that the specimen of 

 fig. 56 was, in ali probability, not a true dorsicole, but a young disc- 

 form, which, in early life, had chanced to attach itself to the side 

 wall of a larger hermaphrodite. 



As to paragrapli 1 (pag. 263) I bave never felt myself under the 

 least Obligation to investigate M. cirriferum^ for I bave never made 

 or desired to make any new statements about it. If dorsicolous 

 forms had occurred in this species, it would not bave been »quietly 

 ignored«. There is no reason for supposing that the sexual conditions 

 must of necessity be the same in both species, for among closely 

 allied species both the hermaphrodite and dio3cious states may obtain 

 (e. g. Polygordim). And does not Wheeler himself (pag. 234) state, 

 that »il/, cirriferum is virtually hermaphrodite from the beginning 

 of its sexual development«? 



In Paragraph 2 (pag. 264) it is with justice urged, that it has 

 never been shown, that the dorsicolous forms do not grow beyond the 

 stages found by me. But as little has it been proved that they do 



1 This phrase is, peihaps, not a very happy one, but it has the advantage 

 of having beau used by Darwin in his Monograph on the Cirripedia. There, 

 as is well known, Daravin discovered what he termed »complemental males«, 

 regarding the originai sexual condition of the group as dioecious. More recently 

 HoEK has endeavoured (Challenger Eeports Voi. 10) to establish a protandrous 

 hermaphroditism for the Cirripedia, to my mind with little success. But it 

 never occurred to the Dutch author to use such expressions as that it »pleases« 

 Darwin to cali certain things complemental males. Fortunatel}^ there are 

 zoologists, who can ditfer from their predecessors without using offensive 

 phrases. 



2 The dorsicolous forms of Prouho (7). 



