November 8, 1912] 



SCIENCE 



641 



Eesting epithelial cells from the skin of the 

 Amblystoma larva were dissected for com- 

 parison. These cells are quite elastic. If a 

 portion of the cytoplasm or nucleus be cut 

 away, the remainder of the cell undergoes no 

 demonstrable change in form. There is no 

 evidence of a loss of substance from the 

 nucleus when it is out or torn. The nucleus 

 in this cell is a quite concentrated gel. The 

 intercellular matrix is non-viscous and highly 

 elastic. 



Extended studies in this field will be pub- 

 lished later. 



G. L. Kite 



Egbert Chambers, Jr. 

 The Marine Biological Laboratory, 

 "Woods Hole, Mass., 

 September 25, 1912 



EXPERIMENTS WITH DESICCATED THYROID, THYMUS 

 AND SUPRARENALS^ 



This preliminary study of the effects of feed- 

 ing the desiccated endosecretory organs was 

 made on rabbits, guinea-pigs and fowls during 

 June, July and August of the present year. 

 The chief aim was to determine what propor- 

 tion of the offspring of females given an excess 

 of the dry substances were viable. The propor- 

 tion of deformed offspring is not significant, 

 but the action of the drugs on the fetuses and 

 sucklings seems worthy of a brief note. 



RESULTS IN THE PREGNANT RABBITS 



From four to ten capsules (.Y6-1.9 gm.) of 

 thyroid were given daily to rabbits during the 

 last 20 days of their pregnancy, with no appar- 

 ent symptoms of thyroidism. The offspring, 

 however, either died at birth or during the first 



' From the Station for Experimental Evolution, 

 Carnegie Institution of Washington. 



three days of lactation. Before their preg- 

 nancies it was found that from .38 gm. to .57 

 gm. of thyroid sufficed to produce extreme diar- 

 rhea and very rapid heart action; no exoph- 

 thalmos developed. Weight decreased rapidly 

 with .57 gm. 



It was noted that if the offspring were not 

 dead at birth and the heavy doses of thyroid 

 were discontinued during lactation, the off- 

 spring lived. 



In the case of one female of this thyroid 

 group, preliminary feeding with thyroidectin 

 had taken place until six days before parturi- 

 tion, when doses of thyroid increasing from 

 .38 gm. to 1.52 gm. per diem were administered 

 by the capsule method. The lactating young 

 were killed on the third day of this treatment, 

 although they had gained somewhat in weight 

 during that time. 



In the case of the thymus-treated females, 

 the resistance to heavy doses (2.16-2.17 gm.) 

 during the latter half of pregnancy also held. 

 The offspring of three females were killed by 

 the drug at an early age; one litter of the 

 fourth succumbed at the third day of lacta- 

 tion, the other litter was bom two days after 

 the cessation of thymus feeding and though 

 smaller than either of the two litters of the 

 control rabbit in this series, lived. The effects 

 of thymus on the adult females not in the later 

 stages of pregnancy were similar to those in 

 the non-pregnant females. 



Unfortunately, but one of the suprarenal-fed 

 rabbits gave birth during my period of ex- 

 perimentation. Her young were alive on the 

 twenty-fifth day after birth, having grown 

 much more rapidly than those of the control. 

 Two of this litter were placed with one of the 

 thymus females whose young had just died, on 

 the day after birth, and two days later were 

 dead. A third suckling from the suprarenal 

 female was placed with the thyroid female 

 which was receiving diminished doses during 

 lactation, and this last adoption was success- 

 ful also, but with the result that the stranger 

 grew 5 gm. more in two days than a brother 

 with the same initial weight in the home nest. 



No discussion of these facts is needed; the 

 table speaks for itself. These females were 



