No. 543] SHORTER ARTICLES AND DISCUSSION 



157 



translation by Chappellier, 31 and also the recent works by Baur, 32 

 Haecker, 33 and Goldschmidt, 34 will be found very useful to the 

 general student of Mendelism. 



W. W. Stockberger 



U. S. Department of Agriculture 



THE RANGE OF SIZE IN THE VERTEBRATES 



A small shrew, Microsorex winnemana, recently described 

 from Virginia by Preble, is said, if conclusions from but two 

 specimens may be drawn, to be the smallest species of shrew and 

 therefore the smallest mammal yet known from America. 1 These 

 specimens measured 78 and 86 mm., respectively, in total length. 

 Microsorex hoyi (Baird) of the eastern and central states aver- 

 ages from 82 to 88 mm. and Sorex fontinalis Hollister and Sorex 

 personatus Geoff roy are but slightly larger. Blarina parva (Say) 

 a short-tailed shrew, averaging in total length about 75 to 80 mm., 

 is in this respect smaller than M. winnemana, but much larger 

 in breadth, cranial and other characters. The smallest existing 

 mammal is probably a minute Crocidura of the subgenus 

 Pachyura from Madagascar. 



The Insectivora, essentially an archaic and primitive group, 

 reached its highest development in point of numerous and di- 

 verse adaptations in the Middle Eocene, from which there has 

 been a gradual and steady decline. Sorex is known from the 

 Middle Oligocene, Talpa, the mole from the Upper Oligocene 

 and Erinaceus, the hedgehog from the Lower Miocene. These 

 are some of the oldest of existing genera of mammals. The 

 Malayan genus Gymnura, an Erinaceid, was said by Huxley 2 to 

 possess the most generalized structure of all placental mammals. 

 The persistence of the group is without doubt due in a large part 

 to the small size and relative inconspicuousness of its members. 



31 Chappellier, A., "Kecherches sur des hybrides vegStaux (Traduction 

 francaise). Bulletin Scientifique de la France et de la Belgique, Vol. 41, 

 1907, pp. 371-420. 



82 Baur, E., "Einfiihrung in die experimentelle Vererbungslehre, ' ' Berlin, 

 1911. 



"Haecker, V., < < Allgemeine Vererbungslehre," Braunschweig, 1911. 

 14 Goldschmidt, E., "Einfiihrung in die Vererbungswissensehaft, " Leip- 

 zig, 1911. 



'Proc. Biol. Soc. Wash., Vol. 23, p. 101, 1910. 



