48 
Transactions of the 
It was only a few weeks ago that Mr. Bolton of Stourbridge 
very kindly sent me a group of Lacinularia socialis on a small piece 
of myriophyllum ; and after spending some time in enjoying the 
beautiful sight ( quite a new one to me) of a fully-expanded healthy 
cluster of Lacinularia, seen with a dark-field illumination under 
a low power, I changed the objective and illumination, and began a 
systematic inspection of one of the group. I soon discovered that the 
animals were loaded with eggs, and almost at the same instant saw 
a young Rotifer playing round one of the females in the usual male 
fashion. I at once endeavoured to catch and isolate it, and on suc- 
ceeding found that it was a male, in the usual aborted condition, but 
differing in shape and proportions from any that I had seen before. 
As the weed was perfectly clean, and had nothing on it but this 
cluster of Lacinularia, I had no doubt that it was the male of that 
rotifer : but to make quite sure I clipped away everything from the 
group, and then dropped it into a small tube of clean water. In 
this the eggs hatched day after day, supplying me with dozens of 
the same male, so that I had every opportunity of studying its 
form and structure. 
Fig. 8 is a side view of this creature. It will be seen that it 
consists of little else than a large testis (a) ending in a hollow 
cylindrical penis ( b ), and nearly filling the whole internal space of 
the body. Of mouth, oesophagus, mastax, or stomach, it has not 
even a vestige. There is a large nervous ganglion (c) giving off 
nervous threads to two red eyes, and a dorsal antenna (d). 
Tortuous tubes with vibratile tags were visible above the testis, 
and could be traced partly down the animal’s sides ; while above the 
testis between it and the ganglion (c) I repeatedly thought that I 
caught sight of the delicate outline of a contractile vesicle. At first 
sight this seems a most unusual position, but, if I am right as to 
its existence, it really holds its normal position with respect to the 
testis, and is only apparently thrust out of its proper place by the 
monstrous size of that organ. 
Large cilia could be seen lining the passage through which 
the penis could be protruded, as well as the cup which terminated 
the short pointed foot. 
My good luck with Lacinularia encouraged me to make a 
deliberate effort to find the male of Floscularia Campanulata, 
which was I knew growing in fair abundance in a pond not far off, 
and I have at last been successful in finding it, and in seeing it 
(when newly hatched) force its way through its mother’s tube. 
The Floscules were growing on algae attached to the stems of 
water-lilies, and the first thing to be done was to cut up the stems 
in lengths at the pond’s side, and by the aid of a lens to pick out 
the pieces where there were good-sized clusters of them ; for these 
tube-dwellers have a choice as to depth and light, and even as to 
