308 Proceedings of the Royal Society of Edinburgh. [Sess. 
but much smaller than the corresponding appendage of an adult male. The 
right gonad was an ovary and contained nearly ripe eggs, the left one was 
a functional testis. A second specimen of the same species, found in May, 
1873, had the male “ habitus,” but both its antennules and the abdomen 
were of the female type. The right first trunk-limb was similar to that of 
the male, and on this side a vas deferens was present ; the left side of the 
specimen and the reproductive organs were not examined. 
Of the four specimens recorded by Kurz, two were stated by him to be 
true hermaphrodites, each having an ovary and a testis ; the other two were 
examined only externally, so that whether they were true hermaphrodites 
or only pseudo-hermaphrodites was not determined. Kurz put forward a 
curious explanation of the occurrence of these abnormal examples. He 
stated that they occurred about the time when the first males began to 
appear, but while they were still rare, and he regarded these abnormal 
specimens as representing forms transitional between females and males. 
Grochowski * * * § has recorded an example of Leptodora hyalina Lilljeborg 
( = L. Jcindtii (Focke) ), in which one antennule was short, as in the female, 
and the other long, as in the male, and a female specimen of the Chydorid 
Rhypophilus personatus Schodler ( = Pleuroxus uncinatus Baird), in 
which the rostrum was said to be of the form usual in males. Both these 
specimens, regarding the gonads of which no information was given, were 
found among batches of females of their respective species collected towards 
the end of summer. 
Woltereck j- noticed, among the structural irregularities in some of his 
specimens of Daphnia, the occurrence of “ Zwitterbildung,” but has not 
described these hermaphrodite examples. 
KuttnerJ has recorded observations on a series of abnormal Daphnia 
pulex, which appeared in her extensive culture-material. The starting- 
point of the series was a female which differed from the normal only in 
having rather longer antennules and a shorter rostrum. Among its first 
brood appeared a female in which the antennules were as long, and 
exhibited the same structure, as those of a male.§ The second to the 
twelfth broods (except the fifth, which died before it was examined) were 
* “Uber Hermaphroditismus bei Cladoceren,” Kosmos, Bd. xxi. (1896), pp. 301-310. 
Abstract in Zool. Centralbl ., iv Jabrg. (1897), p. 414. 
t “Uber natlirliche und klinstliche Varietatenbildung bei Daphniden,” Verhandl. I). 
Zool. Ges ., 1908, p. 239. 
J “Unters. fiber Fortpflanzungsverhaltnisse n. Yererbung bei Cladoceren,” Internal. 
Revue Hydrobiol ., Bd. ii. (1909), pp. 658-667. 
§ Except that, judging from the figure (op. tit., fig. 1), a seta was not present on the 
anterior margin of the antennule. 
