CM 



THE AMERICAN NATURALIST [Vol. XLII 



following table is copied from his last paper (Bulletin of the 

 State University, Lexington, Kentucky, April, 1908) to illus- 

 trate the rather remarkable difference in the time of the ap- 

 pearance of the centers of ossification in the male and female 



Time of Appearance of Centers of Ossification in the Bones . 



the 



and ■ 



'ale: between the sixth and twelfth month. 

 emale: between the second and third year. 

 'ale: when about three years of age. 

 emale: between the third and fourth year. 



emale: at four years of age, or early in fifth year. 



urth and fifth year (preceding 

 id sixth year (preceding tra- 

 ( preceded by 



(multangnlum <j ^ ^ ^ g . 



pezoid). 



Pisiform f Female: between the nintn 



(preceded by 



PLANT CYTOLOGY 



Cytological Studies on Saprolegnia and Vaucheria These inter- 

 esting and important types have been the subject of several in- 

 vestigations dealing with the processes of oogenesis, fertilization, 

 etc., with conclusions at variance in a number of fundamental 

 points. Two papers have recently appeared which should re- 

 ceive careful attention. 



Claussen 1 reports upon oogenesis and fertilization of Sapro- 

 legnia monoica, contributing important evidence on points under 

 dispute through the investigations of Trow and Davis, and pre- 



monoica. Ber. d. Deut. Bot. Gesell., XXVI, p. 144, 1908. 



