574 Journal of Applied Microscopy. 



pathological processes. It is very probable that these processes induce the les- 

 sened resistance of the appendicular wall. The role of this agent should be more 

 and more evident in all infections. In non-specific appendicitis, its importance 

 is so much the greater since infection is always secondary in this affection. 



H. H. w. 



Pearce, R. M. Scarlet Fever, its Bacteriology, From bacteriological investigations no 

 and Gross and Minute Anatomy. Med. and jj j^^ ^^^ thrown on the etiology of 

 Surg. Kept. Bost. City Hosp., 1899. * °-' 



scarlet fever. The microorganisms 



found, named in the order of their frequency, are the streptococcus pyogenes, 

 the staphylococcus pyogenes aureus, and the pneumococcus. The streptococcus 

 is found to be the most frequent cause of general infection, and of infection of 

 the mucous membranes of the nose and throat. There is little if any evidence 

 that any of these organisms have anything to do with the etiology of scarlet 

 fever. Their presence is in all probability due to secondary infection. Infec- 

 tions of the middle ear, antra of Highmore, and of the sphenoidal sinuses are of 

 much importance since they are present as complications in a large percentage 

 of_the cases of scarlet fever, and if in these cases death does not result, these 

 secondary infections may produce chronic inflammatory sequelae. h. h. w. 



NORMAL AND PATHOLOGICAL HISTOLOGY. 



Richard M. Pearce, M. D. 



Harvard Medical School, Boston, Mass., to whom all books and papers 

 on these subjects should be sent for review. 



CURRENT LITERATURE. 



Bezancon et Labbe. The Ganglion Lym- The greater part of this article is 



La^'Ssse MedTcale"^" Feb '^s^'iS^r'"^"^'^' devoted to the histology of the lymph 



node. The description is briefly as 

 follows : The capsule is formed of bundles of fibrous tissue in which are elastic 

 fibers, and in some animals, as the ox, horse, and mouse, smooth muscle fibers. 

 It contains few blood vessels, but many lymphatics. The capsule, forms a com- 

 plete envelope, and at the hilum is reflected on to the vessels, passing with them 

 into the organ. The arteries, on reaching the lymph nodules (so-called follicles) 

 in the interior of the node, divide into a close network of capillaries which 

 radiate through the nodule like the spokes of a wheel (" dispose en fayo7is de 

 roue "). 



The tissue proper is composed of a delicate reticulum in which lie the 

 essential cells of the node. The writers do not attempt to decide whether the 

 reticulum is made up of anastomosing star-shaped cells (explanation of Kolliker, 

 His, and Frey) or of anastmosing fibrils lined by endothelial cells (explanation 

 of Ranvier). 



The essential cells are the lymphocytes, cells with round nuclei rich in 

 chromatin, and surrounded by a slight amount of protoplasm, which when more 



