Eben ¢.Eall 457 
No typical looping occurs till after the gland is in the scrotum and 
the subsequent rapid development has begun. This leads one to sur- 
mise that the sudden growth, which changes the embryonic organ from 
one measuring, 6 mm. x 3 mm. x 2.8 mm. unto the adult gland measuring 
65mm. x 42 mm. x 37 mm., is accountable for this peculiarity of blood 
supply. This seems to be especially plausible when the relative positions 
of the mediastina of the human and pig testes are compared. Probably 
the development is so rapid that the arteries which enter perpendicularly 
Fic. 13. Fig. 13a shows the left testis of an embryo pig 48 mm. in length. 
Then entrance of the perpendicular branches of the capsular artery is shown. 
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Fig. 13b illustrates the depth of penetration of these same arteries in the 
testis of an embryo pig of 87 mm. X 9. 
Fie. 13c shows the entrance and distribution of these same arteries in the 
left testis of an embryo pig of 210 mm. X 9. 
in order to penetrate to the center are of necessity twisted back upon 
themselves in supplying the rapidly growing tubules whose development 
must be toward the circumference. The mediastinum is in the center 
of the gland and hence the tubules in developing radiate from this as a 
center. 
The Blood Supply to the Albuginea—The vascular supply to the albu- 
ginea is shown in Fig. 14. 
Above the large capsular arterial branches and veins which supply the 
