86 Journal of Comparative Neurology. 



419), who states that in a child three years old the ratio of the 

 cerebellum to the cerebrum was i : 6. 



In 18 14 Ignaz Dollinger (8, 19) stated that at the mid- 

 dle of fetal life the cerebellum is proportionally the smallest, 

 being to the cerebrum as i : 24, but that it rapidly increases 

 till at one month after birth the ratio is 1:17, and in the 

 adult it is i : 6. 



In 181 5 Serres (29, 77-107) stated that in the human 

 embryo the cerebellum does not appear until the seventh week 

 of development, and in the fowl until the sixth day of incuba- 

 tion. He also says that the organ is formed in the following 

 manner : two laminse spring from the crura of the cerebellum 

 (Kleinhirnschenkeln) and come to rest against each other at the 

 meson. Later they gradually grow together, after which new 

 lamellae are added both cephalad and caudad, and transverse 

 furrows appear and multiply. 



In 18 1 6 Tiedemann (31, 155) says, "At the begin- 

 ning ot the second month a soft fluid substance occupies the 

 place of the cerebellum. Later in the month two small thin 

 plates arise from each side of the oblongata, along the fourth 

 ventricle, turn inward and rest against each other, but do not 

 unite till later. In the third month they have increased in size 

 and represent the corpora rcstifo}iiiia, called peduncles by Willis 

 and crura by other anatomists." 



There follows a period of about forty-one years during 

 which no attention appears to have been given to the subject. 



The next reference that I find is a work on the develop- 

 ment of the brain by Krishaber (19), published in 1865 ; the 

 next to a description of a fetal brain by Callender (5), in 1870. 



1874. His (14, 106) says, "The cerebellum, in most or 

 ders of mammals is divided into a middle part (vermis) and two 

 lateral pieces separated from it by a furrow. The vermis is 

 formed from the mesal roof of the brain tube, i. e. , out of such 

 constituents as were present before the development of the 

 lateral masses (hemispheres)." 



1876. Mihalkovics (22, 53) says, "The roof of the 

 epencephal (Hinterhirndecke) forms an expanded lamella which 



