RECORDS 133 



valleys which are separated by comparatively barren ridges. 

 The farther apart the valleys, the less intimate is the relation- 

 ship beneath their snails. Although geographical isolation is 

 probably the chief factor in determining the establishment of 

 definite varieties, yet the differing environmental conditions ob- 

 taining in each valley may exert considerable influence. 



Dr. Strong presented a preliminary report, illustrated by lan- 

 tern slides, upon a case of unilateral atrophy of the cerebellum 

 in a child which lived to the age of three years and four 

 months. The principal external anomalies noted were the fol- 

 lowing : the left hemisphere of the cerebellum was almost en- 

 tirely absent ; the right olive was wanting and the transverse 

 pontile fibres on the left side were deficient ; the left half of the 

 pons protruded more than the right ; the right crus cerebri was 

 much narrower than the left ; the left restiform body was 

 smaller than the right, and the superior cerebellar peduncle 

 of the left side was deficient ; the posterior corpora quadrigem- 

 ina were asymmetrical, while the left anterior corpus quadri- 

 geminum was apparently lacking ; the median line of the fourth 

 ventricle was curved with its convexity toward the left, and such 

 structures of the medulla as the clava, cuneus, ala cinerea, and 

 eminentia teres were located or extended further cephalad on 

 the left side than on the right. Preliminaiy transverse sections 

 cut at various levels through the medulla, pons, isthmus, and 

 posterior corpus quadrigeminum showed the following points : 

 only small parts of the right olive and left corpus restiforme 

 were present, and there was a corresponding deficiency of the 

 cerebello-olivaiy fibres ; the transverse pontile fibres on the left 

 side were reduced, but the nuclei pontis were larger on the left 

 side ; the longitudinal pontile fibres were deficient on the right, as 

 shown by the smaller orus cerebri of this side ; the left lemiscus 

 was the smaller, and the left superior cerebellar peduncle was 

 reduced. Other deficiencies were noted, which, however, re- 

 quire further study. Full discussion of the case was postponed, 

 as the research is as yet uncompleted. 



Henry E. Crampton, 



Secretary. 



