326 
POPULAR SCIENCE REVIEW. 
MICROSCOPY. 
An American —-inch Object-glass . — The “Monthly Microscopical Journal” 
says that, according to a statement in an American journal, Mr. Tolies has 
alone made an object-glass of this power ; but the American journal is evi- 
dently unfamiliar with the fact that Messrs. Powell and Lealand have long 
since achieved a similar result. The paper in question says, “ Boston stands 
pre-eminent in the production of exquisite and wonderful optical instruments. 
Mr. Tolies has just achieved the great result of producing a ~ objective for 
microscopic uses — a glass of such difficult construction, that we believe no 
optician has ever attempted it before. The power of this objective is such 
that a single white blood corpuscle covers the entire field of vision. 
Mr. Tolies has produced two of the finest ^ objectives ever constructed, one 
of which is in this city, the other in the hands of a Western gentleman. 
The angular aperture of one is 120° ; that of the other, and the last con- 
structed, is 165°. The objectives are of great excellence, and, in the opinion 
of competent microscopists , far smpasses in defining power and clearness of field 
those of European make A ! ! 
A New Mode of Cataloguing Mici'oscopic Objects. — At a recent meeting of 
the Medical Microscopical Society, a paper was read from Mr. Groves, “ On 
Cataloguing and Arranging Microscopic Specimens,” After describing the 
difficulties generally experienced, he said that he had adopted a method at 
once simple and of universal application. For small collections he advo- 
cated a total absence of classification in the cabinet, though for large col- 
lections he considered it necessary. Th6 catalogue he used, and which he 
would rely upon in all cases rather than the classification of specimens, was 
this : — He took an ordinary alphabeted note-book, and in that noted under 
the proper alphabetical heading every portion of every preparation. Thus, 
for a specimen of small intestine: — Under (I) was entered Intestine, small, 
No. — ; then under (G), Glands, Brunner’s, No. — ; Peyer’s, No. — . Under 
(V), "Villi, No. — ; Villi, lacteals of, No. — ; Villi, invol. muscle of, No. — , 
and so on. This method he found very handy for specimens required for 
demonstration purposes. 
The Structure of the Ovum in Loligo. — Mr. E. Ray Lankester, M.A., has 
read a very valuable essay before the Royal Society, which will be published 
fully, with illustrations, in the “ Transactions,” upon the above and several 
kindred subjects. The following is a short account of the chief points of 
interest in the section devoted to Loligo : — (1) The explanation of the 
basketwork structure of the surface of the ovarian egg by the plication of 
the inner egg-capsule. (2) The increase of the yelk by the inception of 
cells proliferated from the inner egg-capsule. (3) The homogeneous 
condition of the egg at fertilisation. (4) The limitation of yelk-cleavage 
to the cleavage-patch. (5) The occurrence of independently-formed 
corpuscles (the autoplasts) which take part in the formation of the 
blastoderm. (6) The primitive eye-chamber, formed by the rising up of an 
oval wall and its growing together so as to form a roof to the chamber. 
(7) The origin of the otocysts by invagination. (8) The rhythmic contrac- 
tility of a part of the wall of the yelk-sac. (9) The disappearance of the 
