THE MICROSCOPE. 131 



parent and membranous linings of these passages the appearance of 

 gold beater's skin speckled with flour. It is likewise found in the 

 bronchial tubes and their divisions, and even in the bones with 

 which the air sacs communicate. Megnin believes that while the 

 mite may be extremely numerous, so as to cause mucous irritation 

 and induce asphyxia and congestion by obstruction of thebronchiae, 

 and that birds may thus die, yet it is incapable of causing, as Ger- 

 lach and Zundel believe, enteritis or inflammation of the peritoneum. 

 — Scientific American. 



Changes of Uterine Muscular Tissue After Parturi- 

 tion. — Prof. Wojtschechoffsky has examined, microscopically, ten 

 uteri, removed from women who died within thirty-five days post- 

 partum. He offers the following as the result of his investigations: 



1. The fatty degeneration of the uterine muscular tissue, 

 upon which the diminution in size of the uterus depends, begins 

 immediately after parturition, and covers a period of more than 

 five weeks. 



2. The degeneration attacks alike all parts of the organ 

 (fundus, corpus and collum). 



3. It could not be ascertained whether the process began 

 at an earlier period in the outer or inner muscular layer of the 

 uterus. 



4. The interstitial tissue of the uterus does not take an active 

 part in the process of involution. 



5. The process of obliteration of the blood-vessels covers a 

 greater period than the entire involution. 



6. The appearance of free pigment in the uterus is not sta- 

 tionary. — ^Deutsche Med. Zeit. 



Development of the Red Blood Corpuscles. — Feuerstack 

 has published a memoir on this subject. He gives first a brief men- 

 tion of those authors who have sought to trace the development of 

 the red corpuscles from the white; second, an abstract of Hayem 

 and Pouchet's theory of the hsemato blasten; third, of other views of 

 less importance. The author then presents his own observations 

 and conclusions. "We find in the circulation of animals with nu- 

 cleated blood-corpuscles every possible transition between colorless 

 and colored blood-corpuscles. That they are transition stages 

 from the white to the colored cells is shown by the course of de- 



