May 24, 1918] 



SCIENCE 



519 



Laurent, of Marseilles, who refers one to 

 Unger's genus Arfocarpidium and does not 

 venture beyond PhyUites in the identification 

 of the other. 



While not absolutely unique, even if the age 

 is as great as is assigned to them, since some 

 of the leaves described by Fontaine from the 

 Iseocomian of Virginia may be dicotyledon- 

 ous, the Xew Zealand examples are less ambig- 

 uous. It may be pointed out however that 

 Lower Cretaceous and Neocomian are not 

 s.ynonymous terms, as one might infer the 

 author to believe, and no evidence is presented 

 which would indicate that these New Zealand 

 deposits could not be Barremian, Aptian or 

 even Albian in age, and in the last stage 

 dicotyledons are fairly common in both Amer- 

 ica and Europe. 



A table giving the distribution of the New 

 Zealand species in other regions would have 

 added much to the usefulness of the report. 

 E. W. Berry 



The Johns Hopkixs University, 

 Baltimore 



SPECIAL ARTICLES 



THE FACTORS INFLUENCING THE ATTITUDE 



OF THE HEAD IN ANIMALS WITH INJURY 



TO ONE OTIC LABYRINTH 



IIaoexdie, more than a century ago, rec- 

 ognized that the central nervous system par- 

 ticipated in the maintenance of the attitudes 

 of the body as well as in its movements. Re- 

 cently Sherrington has called attention to this 

 function under the head of the postural activ- 

 ity of muscle nerve. The attitude of the head 

 is one of the characteristics of experimental 

 removal of one otic labyrinth in animals, and 

 the analysis of the factors involved becomes 

 of importance from the point of view of the 

 relation of the attitude of the head to the 

 maintenance of the position of the body in 

 space and hence, to the problem of the main- 

 tenance of equilibrium, as well as from its 

 own intrinsic interest. This analysis was be- 

 gim by Dr. A. L. Prince, of Yale,^ in this 

 laboratory more than two years ago, but his 

 service in a base hospital of the American 



1 Proceedings of the Society for Experimental 

 Biology and Medicine, 1916, XIII., p. 156. 



Forces in France led to an interruption of the 

 experiments. We desire to add a brief state- 

 ment of new experiments at this time. We 

 hope later to publish the data in full with Dr. 

 Prince as the senior author. 



The torsion of the head, always seen after 

 removal of one otic labyrinth, with the occiput 

 turned toward the injured side, largely dis- 

 appears after removal of the homolateral cere- 

 bral motor cortex in dogs. The torsion reap- 

 pears if the heterolateral cerebral motor area 

 is removed some weeks or months after the 

 ablation of the homolateral area. 



The torsion of the head is greatly increased, 

 and the rolling movement toward the side of 

 the injured labyrinth, together with the ocular 

 movements (ocular nystagmus) reappear, if 

 the heterolateral cerebral motor cortex is re- 

 moved some weeks after the time of the 

 labyrinthine operation. Rolling movements 

 of the animal to the side of the remaining 

 cerebral motor area reappear, but no nystag- 

 mus, if one cerebral motor area is removed 

 some weeks after bilateral labyrinthine opera- 

 tion.^ 



Our experiments have given a new interest 

 to Magendie's statement that the division of 

 the central nervous system into segments, 

 e. g., medulla oblongata, cerebellum and cere- 

 brum, is an artificial division from the point 

 of view of the physiologist, and that all parts 

 must be considered together in arriving at an 

 estimate of its functions. B. Aroxovitch, 

 F. H. Pike 



The Department of Physiology, 

 Columbia University 



A SLOW-SPEED KYMOGRAPH 



Physiologists and others using the "me- 

 dium-spring" kymographs of the Harvard 

 Apparatus Company, which are not provided 

 with a slow-speed mechanism, may be inter- 

 ested in a simple device I have used for ma- 

 terially reducing the speed of the drum. It is 

 shown in the appended figure. A small hole 

 is drilled in the upper comer of the largest 

 fan, and into it is tied a strong but flexible 



- Unpublished experiments by Drs. Strauss and 

 Friesuer. 



