Page:Proceedings of the Royal Society of London Vol 69.djvu/509

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in the Brain of the Ammoccetc.
489

Zoology in the Owens College, I have been able in a striking manner to confirm the results thus obtained in the New Zealand Ammococte by an investigation of the corresponding organs in one of the European species. Professor Hickson kindly placed at my disposal for the purposes of this investigation a series of transverse sections, which had been cut a short while before by his assistant, but which he had not yet examined, and I was delighted to find in these, with- out the slightest difficulty, the structures which I had previously discovered in New Zealand.

The Owens College Ammoccete was, to judge from the size of the sections, considerably older than the New Zealand specimen, and this possibly accounts for certain differences in the arrangement of the parts under discussion. It appears also to have been treated with osmic acid, while the staining was effected by means of iron Brazilin. The columnar epithelium of the ciliated grooves is perhaps not quite in such a good state of preservation histologically as in the New Zealand specimen, but evidently has much the same character. Beneath the posterior commissure the grooves are widely separated from one another (fig. 4) instead of being in close contact. Anteriorly (fig. 5) they are I think better denned than in the New Zealand specimen, and the left one can be traced a good deal further forwards

FIG. 4.


FIG. 5.