836 REPORT—1896. 
colour, or arrangement of similar organs; it is, however, the origin and history of 
adaptations which interest the morphologist, and his task must be, not primarily 
to draw up genealogical trees, but to correlate these adaptations as far as possible 
to the external conditions which have caused them. 
5. The Olfactory Lobes. 
By Professor Cuarues 8. Minor, Harvard University, Boston. 
The author reports observations on the stratification and on the cell forms to 
be found in the developing and mature olfactory lobes, and deduces the con- 
clusion that the lobes must be regarded as modifications of the cortex cerebri. 
He also emphasises the fact that the form of the cells of the cerebral cortex is 
extremely variable, so that the current descriptions, especially of the pyramidal 
cells, are really more or less conventionalised. These variations greatly facilitate 
the comparison of the cells of the cortex proper with those of the olfactory lobe. 
6. On the relation of the Rotifera to the Trochophore. 
By Professor Marcus Harros, I.A., D.Sc., LS. 
The author gave reasons for regarding the usually accepted affinities of the 
Rotifera to the Trochophore as due to similarity of conditions and to no more 
morphological identity. He regards the Rotifera as primitively aproctous, and 
suggests that the anus has been formed by the fusion of the blind end of the gut 
with a genito-urinary cloaca, This is indicated by the absence of the anus in the 
males of most Rotifers and the females of one family. Again, while the anus of 
the Trochophore is formed from part of the blastoporal area, the proctodeum in 
Rotifera is formed outside this area. The author regards the Rotifera as corre- 
sponding with Pilidum, in which the apical organ has been transformed into glands 
for attachment, as occurs in the larva of certain Echinoderms. All the orientation 
of the Rotifera is, according to this view, comparable with that of the cuttlefish. 
‘ Anterior’ und ‘ posterior’ become replaced by oral and apical ends, ‘dorsal’ 
and ‘ ventral’ by anterior and posterior, while right and left are unchanged. 
7. Statistics of Wasps. By Professor F. Y. Epczwortu. 
By new methods and a new application of old methods (which are described in 
the ‘Journal of the Royal Statistical Society ’ for June 1896) the writer confirms 
the conclusion formerly obtained, that the average duration of a wasp’s absence 
from the nest is about a quarter of an hour in the evening. But for the daytime 
the average duration of a voyage is considerably longer. 
8. Note on Genyornis, Stirling, an Extinct Ratite Bird supposed to belong 
to the Order Megistanes. By Prof. A. Newton, /.R.S. 
9. Report on the Fauna of African Lakes.—See Reports, p. 484. 
WEDNESDAY, SEPTEMBER 23. 
The following Report and Papers were read :— 
1, Report on the Zoology, Botany, and Geology of the Irish Sea. 
See Reports, p. 417. 
