PROGRESS OF MICROSCOPICAL SCIENCE. 
203 
within a very few minutes, so as to become a striking and marked 
feature of its appearance. This raises the question whether the fringe 
of cilia down the body, as described, is a specific characteristic of the 
Stentor Miilleri, or is not rather a mark of the beginning of fission in 
all Stentors, — a question which an amateur naturalist may state, but 
will not presume to express an opinion upon. 
In the instance above reported it is noteworthy that, except in 
the first appearance of the ciliated line down the body, there was 
nothing resembling a division by cutting or splitting. The body was 
of larger diameter than before, both above and below the new disk, 
when it first assumed the form of a protuberance with a ciliated circle 
on its anterior side ; and the subsequent diminution of the diameter 
of the body and tail of the upper individual was gradual throughout 
its length, through the stages shown by the drawings. 
The observations were made with a |-inch objective of low angle, 
but excellent definition and penetration, with the B eye-piece, and the 
situation of the Stentor in the compressor was very favourable for an 
unobstructed view of the phenomena at all stages. 
Swedish Podurans. — The Poduridas, or " spring-tails " of Sweden, 
have been monographed in an elaborate way by T. TuUberg. The 
memoir is accompanied by twelve plates, and enters quite fully into 
the anatomy of these little creatures of so much interest to micro- 
scopists. The work appears in the Transactions of the Royal Swedish 
Academy for 1871. 
The Histology of certain of the Corallinacece. — ^At the meeting of 
the Linnean Society on June 15, Professor Duncan, F.R.S., delivered 
an oral epitome of a joint research by himself and Major-General 
Nelson, R.E., on some points in the histology of certain species of 
Corallinacese. Quekett, about 1851, gave a good account of the 
minute textural peculiarities of the hard structures of corallines 
generally, and in 1866 Rosanoff published a memoir on the Melobesia3, 
therein bringing to light many details of the softer structures omitted 
by the former. Major-General Nelson and Professor Duncan now 
supplement the foregoing by further microscopic investigations on the 
living forms of Bermuda and Britain. On the shores of the former 
island the high and constant temperature conduces to a development 
and growth of the corallines not witnessed on our own seaboard, and 
the colours, moreover, are rich in proportion; for these and other 
reasons a more complete study of their development and physiology 
has been made. Starting from Quekett's and Rosanofi''s labours, the 
recent researches show the presence of remarkable filamentous ap- 
pendages to the dermal layer, which latter is composed of a loose 
cellular envelope, permitting the existence of large sub-dermal areas. 
The interior more aggregated cellular substance has certain radiating 
fibres running through, and which are modified at the joints. The 
growth of the cell-structure, semilunar bodies developed in the 
primordial utricle, the manner in which the deposition of carbonate of 
lime takes place, and other interesting facts, the authors elucidate 
and place on record. 
