244 The Microscope. 



The next meeting occurs August 7, at which date J. C. Falk 

 and William Ilhardt will present subjects for consideration. , 



THE TROY SCIENTIFIC ASSOCIATION. 



'* I HIS Association held its eighteenth Annual Reception and 

 -*- Microscopical Exhibition May 21, 1888. Some one hundred 

 and one slides were shown. There were three tables devoted to 

 specimens — inorganic, vegetable and invertebrate. A noticeable 

 feature of the exhibition was a lemonade table, which was, no doubt, 

 approved by the guests of the Association. 



ELEMENTARY DEPARTMENT. 



A COURSE IN ANIMAL HISTOLOGY. 



FRANK W, BROWN, M. D. 



FOURTH PAPER. 



'"T^HE Connective Tissues. — Connective tissue, in one or other 

 -*- of its several forms, is found in every organ and structure of 

 the body, with the exception of certain epithelial surfaces and their 

 offshoots, the hairs. Although its function is a purely mechanical 

 one, serving to support the essential cells of an organ, or in its 

 purer form as bone, to sustain the body, it plays an exceedingly 

 prominent part in health and disease. There are few morbid changes 

 in which it does not participate. Less complicated in structure and 

 requiring less nutrition than the cells it sustains, its tendency in 

 morbid processes, not destructive in character, is to increase, thriving 

 at the expense of, and crushing out, the cells. In destructive pro- 

 cesses, it is the last to yield, and when destroyed the first to become 

 restored. 



Though differing widely in appearance in their several forms, the 

 connective tissues have much in common. They are developed from 

 the same layer of embryonal cells, and show their relationship, when 

 at maturity, by a tendency, under certain circumstances, to pass from 

 one form to another. Composed in the embryo almost entirely of 

 cells, they are, when fully developed, made up mostly of intercellular 

 substance, the cellular elements being few in number. Finally, they 

 are composed of chemically allied substances. The cells of connec- 

 tive tissue are of two sorts, (1) fixed cells and (2) wandering migra- 

 tory or lymphoid cells. The former are the constituent cells of the 



