PHYSIOLOGY, CHEMISTRY AKD PATHOLOGY 21 



merely from the concomitant fall in blood pressure, namely, a slowing of 

 the flow, or in some cases an absolute stoppage. The injections made 

 with extracts of the fresh glands before drying, either by boiling or extract 

 ing in warm salt solution, were in all essentials similar to those with the 

 dried powder. In order to see whether the effects recorded were due to 

 the pineal extract itself, or to the cholin content of the gland, 1/300 grain 

 atropin was used in a series of injections along with the pineal extract. 

 The results obtained from these injections varied considerably, but in all 

 cases a slight fall was demonstrable and, in at least one case, the fall was 

 measurably as great as that caused by an injection of the extract without 

 the atropin fifteen minutes previous. Horrax has found, therefore, in 

 agreement with his predecessors, that intravenous injections of the extracts 

 of the pineal body of young animals cause a constant but relatively slight 

 fall in blood pressure. The injection causes no increase in the flow of cere- 

 brospinal fluid and the fall of blood pressure, moreover, is not due entirely 

 to the cholin content of the gland. 



McCprd(fr) (1915) carried out twenty animal experiments in which 

 pineal extracts were injected into the jugular veins of dogs anesthetized 

 with chloretone. The pineal extracts were prepared from fresh glands by 

 grinding in a mortar with saline solution. The usual dose was one gland 

 in 2 mils of solution. The results obtained were contradictory. Some of 

 the dogs were quickly killed by a single injection of the extract from one 

 gland. The phenomena associated with the injection were a rapid and 

 marked fall in blood pressure, depressed and irregular heart and intense 

 venous engorgement, followed by death. However, in the larger number 

 of animals it was found that a dose of one, two or more glands prepared in 

 the same manner brought about no observable effect. 



In general, it may be maintained that the immediate results attending 

 the intravenous administration of extracts from the pineal gland are not 

 usually pronounced. The intensity of the several activities reported as 

 occurring is so slight that at the present time no great significance may be 

 attached to them. In the light of Abel and Kobota's findings, that in 

 all tissue of the body histamin is present, practically all of the immediate 

 results following pineal administration may be attributed to the small 

 quantities of this amin contained in the gland. 1 



1 Vincent has stressed the fact that such observations as those quoted cannot be 

 given any weight as evidence of hormone content in the extracts. Similar results 

 whether due to histamin or not can be obtained with a variety of extracts, includ- 

 ing quickly prepared extracts of the experimental animal's own glands. R. G. H. 



