THE PITUITARY GLAND 53 



calls "tethelin" (from the Greek "tethelos," grow- 

 ing) , and which he considers the growth -promoting 

 factor. Its analysis shows it to be related to the 

 phosphatids, a group of important physiological 

 compounds present in all cells. These results need 

 confirmation. 1 



The function of the posterior lobe of the pitui- 

 tary. If surgical methods and clinical observation 

 point to the anterior lobe as the growth-promoting 

 portion of the pituitary, what, it may be asked, is 

 the function of the posterior body? We have al- 

 ready seen that surgical removal of the posterior 

 body is not followed by any extreme changes in the 

 animal; on the other hand, an extract of the pos- 

 terior lobe, when injected into the blood, produces 

 an increase in blood pressure, much like adrenaline 

 from the adrenal glands (which see). Though 

 Oliver and Schafer were the first (in 1895) to show 

 the effects on blood pressure of an injection of an 

 extract obtained from the whole gland, it was left 



1 For the benefit of the student of science the principle that 

 Robertson employs in isolating his tethelin will be given; un- 

 doubtedly much of value is to be found in this pioneer, though 

 somewhat inconclusive study: The anterior lobe is ground with 

 anhydrous sodium and calcium sulphates, dried over the water 

 bath, pulverized and extracted with boiling alcohol, filtered, and 

 the filtrate evaporated somewhat under reduced pressure, mixed 

 with one and one-half times its volume of ether, the precipitate 

 redissolved in alcohol and reprecipitated with ether. The final 

 product is dried over sulphuric acid at 30 to 35 degrees (cent.). 

 "From the constancy of its phosphorus and its nitrogen content 

 the substance would appear to be a chemical unit." Professor 

 Robertson has not yet ascertained its exact chemical configuration. 



