GROWTH AFFECTED BY FEEDING DUCTLESS GLANDS 303 



ing time, and each day (before feeding) for about a week, but 

 thereafter the interval between weighings was gradually in- 

 creased. 



The autopsy technique employed by Jackson ('13), with a 

 few modifications, was used. The various organs were placed 

 in a moist chamber when taken from the animal and weighed 

 when all had been removed. The thyroid and thymus were 

 freed from their capsules. In the younger groups of animals 

 the mesentery and pancreas were removed from the stomach 

 and intestines. These cases are marked (c) in the tables. 



All the organs were weighed in closed containers to 0.1 mgm. 

 The skeleton was prepared by heating the body (eviscerated 

 and skinned) at 90 degrees centigrade for 2 or 3 hours in 2 per 

 cent aqueous 'Gold Dust' (a proprietary soap powder) solution. 

 The skeleton (including cartilages) was cleaned, drained care- 

 fully, and weighed, and then dried for 2 weeks (in an oven heated 

 at 88 to 90 degrees centigrade) to constant weight and weighed 

 again. This technique gives fairly constant results. 



In the final averages shown in the various tables, extreme 

 data are in a few cases excluded. (These extreme cases were 

 probably due either to experimental error or to abnormal 

 variation.) 



The tables show only the averages of individual data. A copy 

 of the original observations have been filed at The Wistar Insti- 

 tute of Anatomy and Biology, Philadelphia, where they may be 

 consulted by those interested. 



The material for feeding was obtained every 2 weeks by the 

 author in person, from newly-killed calves 6 to 10 weeks of age, 

 and ground fine in a kitchen meat-grinder. Some of the sub- 

 stance of each kind was spread out thin and dried before an 

 electric fan at room temperature. The material was quite 

 dry within 5 to 10 hours of the death of the calves. It was 

 diluted with known amounts of milk sugar for measuring. A 

 portion of each kind was kept fresh (at from zero to 5 degrees 

 centigrade). No constant difference in the effects produced 

 by the fresh and dry glands was noticeable, so in grouping the 



