PROCEEDINGS OF SOCIETIES. 
39 
times at which these creatures came forth ; he got a batch of them now 
about once in every ten days : this was from the same mussel as he had 
last summer. 
Mr. Loy asked if Mr. Badcock had ever dissected a fresh-water 
mussel and found any of these creatures in it, or whether he knew of 
anybody who had ever done so. He had himself dissected a great 
many, but had never yet been able to find any of them. 
Mr. Badcock said he had never found any in a mussel, and never 
found any near a mussel except once. 
Mr. Slack asked if Mr. Loy had looked for any sporocysts ; he 
thought all one could expect to find would be some minute white 
threads in the liver and genital organs. From the translations and 
drawings given in the ' M. M. J.' for April, it would seem that previous 
observers had left much to be elucidated, and Von] Baer had used too 
low a power to enable him to make out the anatomical details which 
Mr. Stewart had described. 
Mr. Loy said he had got mussels of various kinds, and had obtained 
them from different sources, but could neither find the creature nor any- 
thing like it — not even the threads mentioned by Mr. Slack. 
Mr. Badcock suggested that perhaps Mr. Loy had looked for the 
creatures at the wrong time of year ; he found they disappeared 
altogether during the winter months. 
Mr. Loy said he looked for them in January, February, and March : 
he had tried all sorts of mussels from all sources, and had never been 
able to find a trace of anything resembling them. 
The President thought it would be of much interest to determine 
if possible the alimentary system. 
Mr. Slack thought the sporocysts seemed the most interesting 
things connected with these creatures ; it appeared that they branched 
out and germinated, and cast off germs which resembled the early 
stages of the parent creatures. 
Mr. Badcock was afraid it would be premature to say that he had 
traced them to a second stage ; but he might say that he had kept some 
of them for some time in a bottle, and had found in place of them a 
creature somewhat resembling the other, with the central body 
surrounded by cilia, and having a rudimentary central tail. He had 
on a former occasion attempted to bring one in this condition to the 
Society for exhibition, but unfortunately it got crushed in coming. 
Mr. Slack read a paper " On the Use of Mr. Wenham's Eeflex 
Illuminator." (See p. 5.) 
Mr. Mclntire said he could speak to the difficulties attending the 
use of the apparatus when used with an objective of more than 100°. 
The suggestion about stopping down the angles was a good one ; some 
very beautiful effects might then be produced. 
Mr. Crisp thought the most convenient apparatus for stopping 
down was the iris diaphragm. 
Mr. Wenham inquired whether Mr. Crisp had done this in the 
case of very high powers, because he thought in those cases it would 
be apt to cut off the field in consequence of the diaphragm being so 
much behind the conjugate focus. 
