316 Proceedings of the Royal Society of Edinburgh. [Sess. 
functional. The specimen was isolated, and the two broods of young — 
each consisting of four females — which it produced, were examined and 
found to be normal. 
It is noteworthy that, of the four abnormal antennules of Daphnia pulex 
recorded in this communication, two (those of specimens II. and IY.) present 
resemblances to the antennules of species of Ceriodaphnia, a fact which 
suggests the close genetic affinity of this genus with Daphnia. 
The occurrence in female Daphnia pulex of an antennule of male form 
may be regarded as evidence of the presence in the female of male characters, 
which, in normal cases, are in a completely latent state, and is not in- 
consistent with the conception that the female is a heterozygote. These 
and other cases of pseudo-hermaphroditism in the Crustacea would appear 
to indicate that the secondary sexual characters are not indissolubly linked 
with the primary ones. In each of the four cases here recorded it will be 
noted that the antennule — the first of the series of appendages to appear 
in development— is the only aberrant appendage ; it is evident, therefore, 
that after the antennule had been formed the normal mode of growth of 
the appendages was at once restored.* Further, two of the examples 
(III. and IY.) above described, f the young of which were available for 
examination, differ from the aberrant forms recorded by Kuttner (see, pp. 
308, 309) in that they produced normal offspring, the structural peculiarities 
of the antennule not being transmitted. 
* The only other departure from the normal mode of growth was in regard to the 
an tero- ventral edge of the right valve of the carapace in specimen II., which presented almost 
the configuration of that of a male (see p. 313). 
t The young of the first specimen (I.) had been for a considerable time under a cover- 
glass, in a limited amount of water, before the abnormality of their parent was noticed, and, 
unfortunately, they proved to be no longer viable. 
(Issued separately September 5, 1913.) 
