Microscopical Society. 3787 



observations by which he considers he has established the correctness of his former 

 assertions. The object of the paper was therefore to adduce proofs, not of the vege- 

 table nature of Volvox globator, for on that point both gentlemen agree, but of the 

 cellular nature of certain appearances in that body. The author described the hexa- 

 gonal cells which form a peripheral stratum in the Volvox as being exceedingly diffi- 

 cult to detect in the living organism, and gave an account of their various appearances 

 under different circumstances, stating a^so that difference of locality alone is sufficient 

 to produce very varied appearances, as well as differences in the time of the year. 

 The radiating threads which connect the cells were described at great length and mi- 

 nutely detailed, and the conclusion arrived at was that these threads consist partly of 

 the ductile mucilaginous membrane of the protoplasm, and partly of its contents, the 

 latter being present in various proportions. He also instituted a comparison between 

 the cells in certain Ulvaceous plants and those of Volvox, and stated that he consi- 

 dered the vesicles of the latter to be of precisely the same character as those of the 

 former, and consequently that they are, in every sense of the word, real cells. The 

 author next investigated the origin of the superficial pellicle of Volvox, which he con- 

 siders as formed by the consolidation of the cell-walls ; and then proceeded to endea- 

 vour to determine the relative periods at which the cells, the superficial pellicle, and 

 the cilia are developed, and expressed his opinion that the cilia are the first to make 

 their appearance, the cells and outer pellicle being subsequent growths. The nature 

 of the fluid within the Volvox formed the next subject for discussion ; this he consi- 

 ders not to be water, but apparently mucilage. He then pointed out the close analogy 

 that exists in the development of Volvox globator, and that exhibited by many of the 

 lower Algae and Conferva? ; and concluded by expressing his opinion that every fact 

 brought to light by this inquiry tended to confirm his previous conclusions, namely, 

 that the affinities of the Volvox are with the vegetable rather than with the animal 

 kingdom. 



October 27, 1852 — George Busk, Esq., in the chair. 



A paper by Joseph Delves, Esq., " On the Application of Photography to the Re- 

 presentation of Microscopic Objects," was read. After some preliminary observations 

 the author stated that the only arrangement necessary for the purposes of photography 

 is the addition to the microscope of a dark chamber, similar to that of the camera 

 obscura, having at one end an aperture for the insertion of the eye-piece, and at the 

 other a groove for carrying the ground glass plate. This dark chamber should not 

 exceed 18 inches in length, as, if longer, the pencil of light transmitted by the object- 

 glass is diffused over too large a surface, and a faint and unsatisfactory picture is the 

 result. Another advantage is that pictures at this distance are in size very nearly 

 equal to the object as seen in the microscope. The time of producing the picture va- 

 ries from 5 to 15 seconds. The author also made some remarks upon the mode of ma- 

 nipulating, and concluded by calling attention to some very beautiful specimens that 

 were afterwards presented to the Society. — /. W. 



