ss 



Scientific Proceedings (105). 



by Clark was followed as closely as possible. To begin with, the 

 amount given by him was administered, viz, the equivalent of 

 about 20 mg. of fresh pituitary substance (anterior lobe), to 

 each hen individually, in a gelatine capsule, and when no result was 

 obtained the dose was doubled and later trebled. In no case was 

 any distinct effect produced, the egg-laying curves running prac- 

 tically parallel with those of the control pens. Single Comb 

 White Leghorns were employed. 



52 (1512) 



Some conditions affecting thyroid activity. 

 By W. B. Cannon and P. E. Smith. 



[From the Physiological Laboratory, Harvard Medical School.] 



1. Gentle massage of the thyroid gland in the cat for two or 

 three minutes will cause an increased rate of the denervated 

 heart amounting in some instances to 33 per cent, over the basal 

 rate. The development of the maximal increase of rate is usually 

 slow, requiring from thirty to sixty minutes and passing off in a 

 similarly slow manner. 



2. Massage of another gland, e.g., the submaxillary, does not 

 cause this effect. 



3. The augmentation of heart rate caused by thyroid massage 

 occurs in the absence of the adrenal glands. 



4. Stimulation of the cervical sympathetic trunk as it leaves 

 the stellate ganglion induces a similar augmentation of the rate 

 of the denervated heart: this does not occur if the thyroid gland 

 has previously been removed. 



5. If the cardiac fibers from the stellate ganglia are severed, 

 as well as the vagus nerves, and an afferent nerve such as the 

 sciatic or brachial is stimulated under a degree of anesthesia 

 which will permit reflex retraction of the nictitating membrane and 

 dilation of the pupil, there is a primary increase of rate due to 

 adrenal secretion, followed by the slowly developing increase 

 characteristic of the thyroid effect. 



6. If the vagi and the cardiac fibers of the stellate are cut, 



