BIOLOGICAL AND MICROSCOPICAL DEPARTMENT. 3 



April 4th. 



Director S. W. Mitchell, M.D., in the Chair. 



Eleven members present. 



The Corresponding Secretary reported the presentation of a copy 

 of Lieut.-Col. J. J. Woodward's Report on the Magnesium and 

 Electric Lights as applied to Photo-Micrography ; illustrated by a 

 number of large photographs. 



Dr. S. "W. Mitchell exhibited a slide showing the ova of Bit- 

 harzia hcematobia, believed to cause the intermittent Hcematuria of 

 the Cape of Good Hope and Natal, the specimen having been for- 

 warded to him by his friend Dr. Harley, of London ; and made 

 some remarks upon the parasite. 



Dr. James Tyson resigned the position of Recorder, and Dr. J. G. 

 Richardson was elected to the vacancy. 



April 18th. 



J. Gibbons Hunt, M.D., in the Chair. 



Eighteen members present. 



Dr. Wm. F. Norris made a verbal communication in regard to 

 the use of weak solution of nitrate of silver and chloride of gold in 

 the preparation of tissues for microscopic examination, which he 

 illustrated by numerous mounted specimens, &c. 



Dr. Hunt inquired what strength of the solution of the nitrate of silver 

 was employed. 



Dr. Norris replied that his ordinary solution was one-half of one percent., 

 and in answer to a question from Dr. Truman, stated that the chloride of gold 

 liquid was of the same strength. Several members having mentioned that 

 they met with nothing but failures in attempting to employ these processes, 

 Dr. Norris remarked that he was at a loss to account for this want ef success, 

 and believed that if the half per cent, solutions were used in a dark room, 

 and the specimens allowed to soak in glycerine slightly acidulated with 

 acetic acid, afterwards exposing them to the light until sufficiently colored, no 

 difficulty would be experienced. 



Dr. J. G. Hunt exhibited some mounted slides of Saxafraga sarmmtosa. and 

 observed that in regard to the stomata in plants the general rule is that they 

 are distributed all over the under surface of the leaves. We find exceptions 

 to this law, however, in some species of Saxafraga, and in S. sarmentosa tin' 

 stomata are grouped in clusters only, and are not found in the cells between 

 the clusters. In other species of the genus the same peculiarity occurs, but 

 this arrangement of the stomata cannot be regarded as a generic feature, be- 

 cause some of the Saxafrages have these organs distributed all over the under 

 surfaces of their leaves. 



Dr. Hunt further remarked that the singular amoeboid movement so often 

 noticed iii the white blood corpuscle seems to be a phenomenon not confined 

 to the animal kingdom. A movement apparently similar may be distinctly 

 observed in the nucleus of the cell of Anacharis alsinattrum, and in the plant 

 the movement appears to be more active than that seen in the blood. 



