EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 247 



was at the same time enabled to appreciate all the changes which the 

 ova produce in the different tissues, and also the changes which the ova 

 themselves undergo, and so follow as it were, under the most favourable 

 circumstances, their developement. Among the embryogenic facts 

 which he was thus able to determine, he cites the formation of the 

 three envelopes of the embryo, the manner in which the vitelline cells 

 become grouped to form the macula germinativa, and, finally, the deve- 

 lopment of the embryo itself, and the movements it performs in its 

 transparent ovum. 



Observations on the alteration of the tissues in which the ovula may 

 be lodged, is soon interrupted by the effusion of coagulable matter, 

 which prevents further microscopic examination. In the lung he 

 observed the pathological products to be deposited around the ova, and 

 giving rise in this way to the tubercular appearance mentioned above. 



M. Griiby injected the ova of many species of entozoa, but without 

 success with the majority. He succeeded best with the ova of a species 

 of Monostoma (Distoma ?) which is frequently found in the bladder of 

 frogs. 



M. Griiby presented to the academy various pathological productions, 

 chiefly relative to the frog, and the development of which was owing to 

 the presence of entozoa. 



. 1. Pulmonary vesicles, filled with tubercular matter. This was a 

 portion of the lung of a frog filled with tubercular matter, presenting 

 all the physical and anatomical characters of tubercle in the human sub- 

 ject, and the development of which was the consequence of the deposi- 

 tion of the ova of entozoa in the lung. 



2. Tubercular matter of the pylorus (of the frog?) by which that 

 orifice was much contracted, and also caused by the deposition of ova 

 between the peritoneum and muscular coat. And several others which 

 do not appear to have any connection with this exciting cause. 



M. Bourgery's Researches on the Intimate Structure of the Lungs in 

 Man and the Mammalia. These researches, embracing many divisions 

 of the subject, are related in as many special memoirs, and include 



1. The normal microscopic anatomy of the lungs, and its physiologi- 

 cal application. 



2. The morbid microscopic anatomy. 



3. Anatomico-physiological inquiries as to the general form of the 

 pulmonary vessels. 



4. Physiological experiments on the capacity for air and the degree 

 of permeability of the lung to air, under different conditions, in the two 

 sexes, and at different ages. 



The first memoir relates to the first of these subjects, and commences 

 with the description of the minute anatomy of the air tubes. When 

 M. Bourgery commenced his investigations, there existed three theories 

 as to the intimate structure of the aerian capillaries, referred respectively 

 to Malpighi, Willis and Helvetius. Malpighi (1661), who was the 

 first to discover the membrano-cavernous structure of the lungs, con- 



