PROGRESS OF MICROSCOPICAL SCIENCE. 
203 
the intermediate structure, never in the Haversian system. This fact 
proves that the substance in these localities is developed from the 
periosteum. The relation which the corpuscles and canaliculi bear to 
the fibres of Sharpey may be briefly stated as follows. The corpuscles 
are placed in the angles formed by the intersection of these fibres. 
The canaliculi surround the fibres, but do not pass through them. 
This last fact, taken into consideration with that of the recurrent 
canaliculi of the Haversian system, proves that the canaliculi are 
spaces left in the substance of the bone at the time of its develop- 
ment, and not fissures made during the preparation of the section. 
Fecundation ofThecaspore Fungi. — The ‘Academy ’ (Jidy 10, 1875), 
in its occasional and very interesting microscopical notes, gives the 
following account of a paper in the ‘ Comptes Rendus,’ to which the 
author’s name is not appended. It gives a description of phenomena 
of copulation observed in Hypomyces aster oplehor us, and Dotliidia 
Bobertioni, the latter parasitic on Geranium Bobertianum (Herb 
Robert). The generative process corresponds with what had been 
previously observed by MM. de Bary, Woronin, andTulasne, in other 
thecaspores. The report observes that “ these interesting facts gene- 
ralize the phenomena already observed in a very different group, and 
help to confirm the opinion that the fecundation of thecaspore fungi 
is effected in the mycelium, and thus precedes the formation of the 
organs that form the spores.” Speaking of spermatia, the report con- 
tinues : “ It is known that M. Tulasne has given this name to bodies 
of very great tenuity developing regularly on the surface of many 
Thecaspores and Uredines, or in special conceptacles, and which have 
been considered as concerned in the work of fecundation.” The dis- 
covery of the fecundation of these fungi by organs springing from the 
mycelium — a discovery to which M. Tulasne contributed — rendered 
very problematical the fecundating action attributed to the spermatia. 
The author of the memoir before us shows that the spermatia can 
germinate when placed under suitable conditions, which, for hypo- 
xylous species, consist in adding to water a little tannin and sugar, 
and leaving them in contact with air. The spermatia of Uredines 
germinate in pure water, but their development appears to be very 
different from that of the hypoxylous sorts. 
Development of the European Lobster. — A writer in a recent number 
of ‘ Silliman’s American Journal,’ whom we take to be Mr. Samuel H. 
Scudder, but whose signature is S. I. S., writes as follows on the above 
subject : Dr. Sars has also recently published a paper of twenty-seven 
pages, illustrated by two autographic plates, on the post-embryonal 
development of the European lobster ( Homarus vulgaris, Edwards). 
He describes and figures in detail the three larval stages correspond- 
ing precisely with the first three stages which I have described in the 
American lobster. Dr. Sars did not receive my papers until after a 
part of his memoir was printed, so that his investigations were wholly 
independent. In a short appendix, Dr. Sars calls attention to the re- 
markable agreement in the results at which we had each arrived, and 
to the excellent opportunity afforded for a careful comparison of the 
