Studies on the Endocrine Glands 289 



seen also to obtain with water-extracts of the gland, both boiled and 

 unboiled ; and with the residue, both boiled and unboiled, after extraction 

 with water. 



Does Alcohol-Extract or Ether-Extract of Thyroid contain 

 the Autacoid which affects the Pancreas? 



Experiments were next devised to determine whether alcohol- and ether- 

 extracts of thyroid have similar etiects to water-extracts. The method 

 of preparation was as follows : — 5 ^rm. of finely ground completely dry 

 ox-thyroid was extracted with absolute alcohol for twenty-four hours, the 

 extract being then filtered. The residue on the filter was again thoroughly 

 washed with absolute alcohol. This residue was completely dried at 37° C, 

 and was then extracted with pure ether for another twenty-four hours. 

 The ether-extract was filtered, and the residue on the filter thoroughly 

 washed with pure ether. This second residue was also dried at 37° C. 

 The alcohol- and ether-extracts were respectively evaporated to dryness. 

 In each case, after evaporation of the alcohol and ether, the residue which 

 remained at the bottom of the beaker was in the form of a soft paste. 

 That from the alcohol-extract will be termed A ; that from the ether 

 extract, B ; and the final residue after successive extraction with alcohol 

 and ether will be termed C. Two rats (group A, Nos. 126, 127) were fed 

 with an addition of A to their food. Two rats (group B, Nos. 128, 129) 

 had an addition of B to their food. Lastly, two rats (group C, Nos. 130, 

 131) received an addition of C. Each addition represented the alcohol-, 

 ether,- and water-extract respectively of 1 grm. of dry thyroid. 



The groups were fed with the above additions during five days 

 (October 26-30). After four days' feeding the appetite of the animals 

 belonging to group C appeared to be affected, but nothing was noticeable 

 in the others. All were killed on October 31. There was apparently no 

 change in the weight of any of the groups. The iodine test reacted 

 positively in the urine of gi-oup C ; a trace of iodine was observable in 

 the urine of group A, but the test was entirely negative for the urine 

 of group B. 



Post-mortem nothing particular was observable. 



Pancreas. — On microscopic examination of the pancreas no 

 departure w^hatever from the normal is to be seen in the rats to 

 which the alcohol- and ether-extracts of thyroid were given, but the 

 pancreas of the animals which were fed with the residue after such 

 extraction w^ith alcohol and ether shows changes similar to those 

 obtained in all other cases of thyroid feeding ; these changes include 

 the appearance of a large number of cells which exhibit mitoses, 

 and a general diminution of zymogen granules in the cytoplasm of 

 all the alveolar cells. 



Summary. — Alcohol- and ether-extracts of thyroid produce no 

 appreciable changes in the pancreas. The residue, after extraction with 



