EFFECT OF THYROID GLAND OX PROTOPLASM. 87 



In the familiar experiments with frog tadpoles, the thyroid-fed 

 line and the control line are, of course, taken from the same 

 batch of eggs, thus being of the same nature and the same age. 

 Similarly, in this case, the bulbs were sprouted in the same 

 nutrient medium, for the same length of time, the sole difference 

 tn u\(. n the experimental and the control bulbs being that the 

 former grew v>'nh a given amount of thyroid material added to 

 the solution. 



I IT comparison with the above table, measurements Minilarly 

 made of the control line are here added: 



TABLE II. 



M I v-' 1- ' Ml'fTED FROM SECTIONS. 15 MlCRA IX THICKNESS, ( '1 A'.jn isstlS 



ROOTS GROWING IN PFEFFER'S SOLUTION ALONE. 



Micra from Tip of Mkia I'min Tip of 

 Root to Periblem. Rom t.. I'l. imne. 



I- -450 555 



a.. ..465 



3- -540 630 



4- .480 540 

 5. .420 480 

 6.. .450 495 

 7- -48o 555 



8 .-450 525 



9 -465 540 



10. . .480 540 



ii -4<>5 525 



12 ..480 540 



13 -435 495 



14 -465 5io 

 15- -420 495 

 16. ..435 495 

 17 -450 5io 

 18. . -495 555 

 19- ... 450 5io 

 20. . .435 495 

 21. .495 570 



. .420 465 



495 570 



... 540 



-.495 570 



495 570 



495 555 



28.... -.405 48o 



29. 450 525 



30.. 495 570 



