1-304 Journal of Applied Microscopy 



chromatin is a violet-purple ; during the karyokinesis of the spermatocytes their 

 chromatin is always a red-purple. The author sums up his results as follows : 



1. The amitotic division of the nucleus, which in most cases indicates a 

 degeneration of the cells, does not always show the approach of final degener- 

 ation. The nuclei of the Sertoli cells divide a considerable number of times, 

 perhaps indefinitely, by amitosis. The spermatogonia resulting from amitosis 

 are the founders of a line of cells which show ultimately more karyokinesis and 

 finally develop into spermatozoa. 



'1. Amitosis in the case noted is the same as that in many others : a phenom- 

 enon of the nucleus only, without an immediate division of the protoplasm. 

 Much later the protoplasm divides. 



3. The nucleolus of the Sertoli cell appears to be a cellular organ of 

 primary importance, it is possibly the carrier of a reserve of hereditary sub- 

 stance. 



4. It is remarkable that the nuclei of the Sertoli cells, the stem nuclei 

 which carry the determinants (Weissmanh) of the species, are really the poorest 

 in chromatin of all the nuclei of the germinal epithelium. The quantity of 

 chromatin which passes into the nucleus of the spermatogonia is infinitesimal in 

 comparison with that contained by the spermatocyte at the moment of karj'O- 

 kinesis. The chromatin of the spermatocyte is then acquired, at least in its 

 mass, and is not hereditary. a. m. c. 



NORMAL AND PATHOLOGICAL HISTOLOGY. 



Joseph H. Pratt. 



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

 papers on these subjects should be sent for review. 



Ewing, J. Malarial Parasitology. Journal of Recent advances in our knowledge of 

 Experimental Medicine, S: 420-401, iqoi. , , , ^ , , • , 



the morphology of the malarial para- 

 sites have been largely due to improved staining methods. Ewing restricts the 

 use of fresh blood to the study of various vital phenomena in the parasite, such 

 as amoeboid movement, vibratory motion of pigment, and ex-flagellation. The 

 discovery of parasites is so much more certain and rapid in stained dry speci- 

 mens that a negative result with fresh blood invariably requires verification by 

 search through a dry specimen, stained preferably by Nocht's method. 



For all ordinary purposes staining by eosin and methylen blue is recom- 

 mended. The solutions used are : (a) a saturated alcoholic solution of alcoholic 

 eosin diluted with an equal quantity of 95 per cent, alcohol, and (b) a saturated 

 watery solution of Ehrlich's rectified methylen blue at least one week old. 



Methylen blue does not stain the young ring forms well. For this purpose 

 Nocht's method is especially useful. The method of Benario and Marchoux as 

 modified by Futcher and Lazear is also of value, as the rings are densely stained 

 and the preparations are permanent. It is employed as follows : Fix the speci- 

 mens five minutes in 95 per cent, alcohol, 100 c. c, to which has been added 



