1900 Journal of Applied Microscopy 



the present writer, who describes them as dense fusiform bodies which appear 

 about the time of the formation of the generative and tube nuclei. The fact 

 that they persist even after the formation of the pollen tube, does not seem to 

 agree with Strasburger's statement that microspores containing such bodies col- 

 lapse later and become more or less completely crowded out. c. j. c. 



J. u- 1 c TT J r- 1 .■ The publishers of I^/ora are to be 



Korschmsky, S. Heterogenesis una Evolution. '^ 



Ein Beitrag zur Theorie der Entstehung der commended for translating this im- 

 Arten. Flora, Erganzungsband. 86 : 240- portant work on the origin of species 

 363, 1901. *^ . . 



and thus making it accessible to the 



large circle of botanists who are not able to read Russian. 



After a laborious and rather unprofitable study of plants in their native con- 

 ditions, the writer turned his attention to garden forms. The most important 

 result of his work is the conclusion that new forms do not arise through a grad- 

 ual accumulation of individual variations, as Darwin believed, but rather that 

 new varieties arise suddenly, showing at once a divergence from the pure 

 species. This sudden appearance of new varieties the author designates under 

 the term Heterogenesis. Not the least important part of the work is a carefully ar- 

 ranged summary of the literature bearing upon the origin of new forms in culti- 

 vated plants. c. J. c. 



CYTOLOGY, EMBRYOLOGY, 



AND 



MICROSCOPICAL METHODS. 



AGNES M. CLAYPOLE, Throop Polytechnic Institute. 



Separates of Papers and Books on Animal Biology should be sent for Review to Agnes M. Claypole, 



55 S. Marengo Avenue, Pasadena, Cal. 



Dekhuyzen, M. C. Ueber die Thrombocyten The author refers to Deetjen's work 



(Blutpliittchen). Anat, Anz. 19: 529-540, (see review p. 1859) and says he had 

 ^ ■ already discovered the nucleated con- 



dition of blood plates. He gives the following technic : A. Study of living cells. 

 This is done in physiological salt solutions, rendered as nearly isotonic with the 

 blood as possible. The osmotic pressure of the serum is determined by Bech- 

 mann's freezing apparatus (method given in Ostwald's physico-chemical tables). 

 For amphibians and lampreys 8 per cent, salt solution is most favorable, having 

 the same freezing point as the blood-serum. All glass vessels used in the prep- 

 aration and preservation of this salt solution are carefully rinsed in fuming nitric 

 acid and much heated ; slides and covers, on account of the film of moisture on 

 them, are similarly treated. Water is distilled in an apparatus made entirely of 

 glass. Rubber is to be avoided. The salt used was purified by repeated melt- 

 ing and recrystallization. The normal salt solutions are preserved in syringe 

 (syphon) flasks made entirely of glass. A glass tube with a stop-cock is fused 

 to the longer tube from the bottle and the shorter is bent and filled with a plug 



