142 CARNEGIE INSTITUTION OF WASHINGTON. 



"The loss of weight or amount of albumen under quinine consists in (o) 

 a loss of total substance, and (6) a disproportionate loss of solids. 



" The loss of solids is accompanied by a loss of nitrogen. When the amount 

 of albumen is later increased, in the after-dosage periods, the nitrogen does 

 not increase in full proportion. The percentage of water remains high in 

 albumen produced in these after-dosage periods. 



"It seems clear that dosage of ring-doves with quinine sulphate causes less 

 than the normal amount of nitrogen to be released by the albumen-secreting 

 gland of the oviduct during the secretion of egg albumen." 



CHEMISTRY OF BRAINS OF ATAXIC PIGEONS. 



Dr. Oscar Riddle, in collaboration with Miss Mathilde L. Koch, 

 of the Psychiatric Institute of the New York State Hospitals, has con- 

 cluded a second study of the chemical constitution of the brains (cere- 

 brums), analyzed separately from the cerebellums and medullas, of the 

 strain of ataxic pigeons which has been developed in our collection. 

 The conclusions drawn from the study are as follows: 



" (1) The brains of birds which have lost a very large amount of the normal 

 control of the voluntary movements (ataxia) show deviations from the normal 

 brain in size and in chemical composition. These deviations are more pro- 

 nounced in the cerebellum. 



" (2) The brains of the ataxics are smaller. The cerebrums are either not 

 reduced or are reduced in very small amount. The cerebellums and medullas 

 (weighed together) are certainly reduced in size. 



" (3) Eight analyses were made of anterior and posterior parts of the brain. 

 Four of these were from ataxic and four from normal birds. The chemical 

 changes found are more definite and pronounced in the cerebellums and 

 medullas than in the cerebrums. The results support our previous conclusion 

 that the differences 'suggest a chemical under-differentiation or immaturity 

 of the ataxic brains.' 



" (4) The pigeon cerebrum and cerebellum strongly contrast with the human 

 cerebrum and cerebellum in the distribution of the several chemical con- 

 stituents. 



" (5) Entire brains of very young and of very old birds were analyzed. 

 Data for the chemical changes in the brain which accompany age have been 

 obtained for a series of ages in the pigeon. Examination of this more exten- 

 sive 'age series' of pigeon brains has enabled us to evaluate much better than 

 in our previous work the relation borne by the various chemical fractions to 

 age. 



"(6) The significance of the results obtained in the present and former 

 series of analyses has been reviewed. The evidence warrants the conclusion 

 that chemical differentiation does not proceed as rapidly in the brain, and 

 more particularly in the cerebellum, of ataxic birds as in the brain of normal 

 birds. 



"More than a year ago several of these ataxic birds were sent to the Neuro- 

 logical Laboratory of the University of Chicago, where Dr. T. Hoshino has 

 made a very extensive neurological study of the ataxic brains. His study is 

 now complete and will be pubhshed simultaneously with our second paper 

 on the chemistry of the brains. " 



