7 
system, seasonal changes in the external sexual characters of the 
adult female, and the character of these changes as seen in 
microscopical sections of embryos, nestlings, and adults. 
Mr. H. C. Caapwick contributed some notes on an imperfectly 
developed specimen of the Sea-Urchin (Hchinus esculentus). Two 
well-marked depressions in the test attracted attention to the 
living animal. Denuded of the spines the test presents the 
appearance of a lump of plastic material which has been pinched 
with thumb and forefinger. Two abnormalities appear in the 
apical system, and abnormal plates occur in ambulacra II, III, 
and IV. Inambulacrum III two plates of normal composition 
are exceptional, in that the pore-pairs of their respective demi- 
plates are almost completely outside the limits of the plate, and 
perforate the adjoining interambulacral plate. Similar irregu- 
larities, though not so well marked, occur in ambulacrum IV. 
Mr. C. F. U. Meex, M.Sc., F.Z.S., communicated a paper 
entitled “The Possible Connection between Spindle-length and 
Cell-volume.” In Sorficula auricularia, Helix pomatia, and Man 
the ratio between the lengths of the mitotic spindle in the two 
spermatocyte metaphases seemed to be identical or almost identical 
with the ratio beween the radii of two spheres, of which the 
volume of one is equal to twice that of the other ; and, since the 
volume of the primary spermatocyte cell in the metaphase is 
presumably equal to twice that of the secondary spermatocyte, 
connection was suggested between the spindle-length and cell- 
volume at this stage. Photo-micrographs are now given, showing 
this ratio in the two first-named organisms; but, in the case of 
Forficula, new preparations have been observed to contain primary 
spermatocyte spindles of excessive lengths, and unless a satisfactory 
explanation can be found for these, the original suggestion must be 
either modified or discarded. 
The study of spermatocyte cells in Man, Triton cristatus, 
Stenobothrus viridulus, S. curtipennis, Forficula awricularia, and 
Helix pomatia proves that the volume may be similar in widely- 
separated organisms, and very different in organisms that are 
closely allied. In the circumstances, increasing somatic com- 
plexity of the organism is not necessarily accompanied by increase 
of the volumes of these cells. 
A paper received from Mr. F. F. Larptaw, M.A., F.Z.S., con- 
tained a further contribution to the study of the Dragon-fly 
fauna of Borneo, and dealt with the Gomphine and Chloro- 
gomphinz, of which a number of new species and subspecies was 
described. 
