PLATE 4 



EXPLANATION OF FIGURES 



R. sylvatica. Organs after fixation. Representative camera-lucida drawings 

 selected from drawings of organs from sixty-nine complete and forty partial 

 autopsies. 



Heart, X 5.1. 



28 Thyroidless larvae. 5/2 to 5/20/18. Alive: Tot., 50 mm., B., 20 mm.; 

 fixed: Tot., 47 mm., B., 19 mm. 



29 Control larva. 4/14 to 5/28/18. Alive: Tot., 48 mm., B., 20 mm.; fixed: 

 Tot., 45 mm., B., 19 mm. 



30 Control frog. 4/14 to 6/5/18. Alive: Tot., 16 mm., B., 15 mm.; fixed: 

 Tot., 15 mm., B., 14 mm. 



31 Thyroidless larva. 5/3 to 10/17/17. Alive: Tot., 58 mm., B., 22 mm.; 

 fixed: Tot., 50 mm., B., 20 mm. 



Liver, X 5.1. Ventral view^ 



32 Thyroidless larva (same as fig. 28). 



33 Control larva (same as fig. 29). 



34 Control frog (same as fig. 30). 



35 Thyroidless larva. 4/14 to 10/5/17. Alive: Tot., 65 mm., B., 25 mm.; 

 fixed: Tot., 61 mm., B., 21 mm. 



Hypophysis, X 20.5. Parallel ventral view and transverse section. 



36 and 37 Thyroidless larva. 5/2 to 6/8/18. Alive: Tot., 45 mm., B., 18 

 mm.; fixed: Tot., 42 mm., B., 17.5 mm. A = anterior, S = superior, and'/ = 

 inferior lobes. 



38 and 39 Control larva. 4/30 to 6/4/18. Alive: Tot., 47 mm., B., 18 mm.; 

 fixed: Tot., 45 mm., B., 17.5 mm. 



40 and 41 Control frog. 4/14 to 6/4/18. Alive: Tot., 16 mm., B., 14 mm.; 

 fixed: Tot., 15 mm., B., 13 mm. The anterior lobe may be in the form of two 

 separate lobes. 



42 and 43 Thyroidless larva. 4/22 to 5/30/18. Alive: Tot., 55 mm., B., 

 22 mm.; fixed: Tot., 53 mm., B., 21 mm. 



44 and 45 Thyroidless larva. 4/12/17 to 7/5/18. Alive: Tot., 72 mm., B., 

 25 mm.; fixed: Tot., 68 mm., B., 24.5 mm. 



Thymus, X 28. Two views of each gland to show the three dimensions. 



46 A and B Thyroidless larva. 5/2 to 6/1/18. Alive: Tot., 41 mm., B., 

 18 mm.; fixed: Tot., 41 mm., B., 17 mm. 



47 A and B Control larva. 4/30 to 6/4/18. Alive: Tot , 43 mm , B., 18.; 

 fixed: Tot., 40 mm., B., 17 mm. 



48 A and B Control frog (same as fig. 40). 



49 A and B Thyroidless larva (same as fig. 35). 



Epithelioid (parathyroid) bodies, X 40.8. Ventral view of the two pairs from 

 each animal 



50 Control larva (same as fig. 29). 



51 Thyroidless larva (same as fig. 28). 



52 Control frog (same as fig. 30). 



53 Thyroidless larva (same as fig. 42). 



Thyroid, X 20.5. Ventral view of the pair in each animal 



54 Control larva (same as fig. 29) . 



55 Control frog (same as fig. 30) . 



G. B. = gall bladder. Other abbreviations and dates as in plate 2. The 

 original drawings are three times as large as these. 



58 



