the Microscopical Society. 
81 
it unnecessary for me to go so deeply into the contents of these 
communications as has been usual at former anniversaries. 
Mr. Shadbolt's paper, containing a variety of useful prac- 
tical information on the habitats and mode of collection of a 
number of beautiful microscopical objects, Vi^as listened to 
with much attention, and elicited many remarks and inquiries, 
and, had it not been already published in the Journal, would 
have demanded from me a more extended notice. 
The paper of Mr. Simonds records an interesting patho- 
logical fact. Asa medical man, T cannot help regretting that 
pathology is a subject on which we have very few communica- 
tions ; for I feel assured that the investigation of the products 
of disease is one of the most immediately useful purposes to 
which the microscope can be applied ; and I believe that such 
communications would be well received, not merely by those 
of my own profession, but by the members generally. 
The paper of Mr. Mummery on the development of Tubu- 
laria indivisa, and those of Mr. Busk and Mr. Williamson on 
Volvox globator, contain a vast amount of well-illustrated 
microscopical observations. 
The same praise is due to Mr. Busk's paper on Starch, 
, which also teaches us the useful lesson, not to be satisfied with 
examining things in their natural state, but, by applying re- 
agents under the microscope, to combine chemical research with 
microscopical observation. 
The subject of Microscopical Photography, on which Mr. 
Delves has favoured us with a communication, accompanied 
by some beautiful specimens, is one of great interest. That it 
will attain a high degree of perfection no one who knows the 
persons engaged in its cultivation can reasonably doubt. There 
is, however, a difficulty in its application, which, I fear, will 
materially limit its use. 
Those who have been in the habit of using the microscope 
since the first introduction of achromatic lenses must have 
noticed that in proportion as the object-glasses have increased 
in aperture and improved in definition they have lost the 
power of penetrating to any depth ; and this has now been 
carried to such an extent that when we examine with a high 
power any but the thinnest objects lying in an almost mathe- 
matical plane, we can only do so effectually with the finger on 
the fine adjustment to regulate the focus for the particular 
point on which the eye is fixed. 
This precision of focus, which is a necessary consequence of 
precision of definition, must have the effect of confining pho- 
tography (except with low powers) to the representation of the 
class of objects above described ; or of only allowing us the 
