120 CARNEGIE INSTITUTION OF WASHINGTON. 



in the air while falUnp; and to land squarely on their feet, together with 

 a correlation of the anatomical factors concerned with this reflex. 

 These investigators find that either the vestibular apparatus or the 

 optic system is able to give rise to impulses during falling that result 

 in rotation of the cat in the air; and they conclude that both of these 

 mechanisms are nonnally employed during such a fall. If either the 

 vestibular apparatus or the optic system is experimentally eliminated, 

 the lack does not interfere with the reflex; but if both are deprived of 

 function, the reiiex does not take place. Regarding the anatomy of 

 the efferent pathways concerned in this reflex, it was estabhshed that 

 either the complete removal of the cerebrum or the removal of the 

 whole cerebral cortex abolishes the reflex. Ablation of both motor areas, 

 however, does not interfere with the reflex, a finding which indicates 

 that the cortico-spinal tract does not participate in the mechanism. 



A paper on the Gasserian gangUon has been pubUshed b}^ Dr. CM. 

 Byrnes, in which he reports certain features of the topography of the 

 ganglion, and describes an instrument which enables him to reach the 

 foramen ovale with greater accuracy and safety. It also reduces the 

 degree of \dsualization necessary in making injections into the ganglion 

 in the treatment of trigeminal neuralgia. He describes the changes 

 that occur in the nerve-trunks and the gangUon as a result of alcohol 

 injections. 



An investigation by von Alten on the development of the pharyngeal 

 pouches in Chrysemys marginata has been pubhshed. It is a descrip- 

 tive study including four embryonic stages — 5 somites, 14somites, 18-19 

 somites, and 22-23 somites, respectively. The author's intention was 

 that this should be prehminary to a study on the histogenesis of the 

 thymus. This plan unfortunately could not be carried out. At the 

 outbreak of the European war he joined the army, but suffered a return 

 of a previous sickness and died on April 3, 1915. His work has been 

 published by Professor Keibel. 



The study of the anatomy of human embryos has been facilitated in 

 this laboratory by the development during the past few years of new 

 technical procedures, which enable us to reconstruct mechanically the 

 different parts of the embryo with much greater accuracy than had 

 previously been possible. An account of these unprovements has been 

 pubhshed by Professor Lewis, by whom they have, for the greater part, 

 been devised. His paper gives the technique now used in photo- 

 graphing sections, estabhshing guide-planes for reconstruction by 

 means of the external fonn, and the preparation of wax molds, in 

 which are made pennanent plaster-of-paris casts of any of the parts 

 desired. It is the permanency and accuracy of these casts that consti- 

 tute their superiority over the ordinary wax-plate reconstructions. 

 Dr. Lewis includes in his paper many technical points and formulae 

 tihat are of value in photographic and wax-plate procedures. 



