LIST OF ILLUSTRATIONS xx jji 



FIGURE PAGE 



416. Epithelial cells from the bladder of the rabbit .... -!.">_> 



417. Transection of the female urethra ..... I.",.; 



418. Diagram of a male genitalia ..... 4.").") 



419. Diagram of female internal genitalia . . 4.~>ii 

 420. Diagrams illustrating the metamorphoses of the indifferent urogeni- 



tal sj^stem into the male and female systems . . i.~>7 

 421. Diagrams illustrating the process of maturation in the male and 



female gametes . .462 



422. Primary spermatocyte of a grasshopper, Hippiscus tuberculatus, 

 showing the compact accessory chromosome among the paler 



mossy prophase euchromosomes, and the idiosome ' . . 4ii4 



'423. Chromosome groups of Schistocerca damnifica . . 473 

 424. Diagram illustrating the behavior of the chromosomes during the 



first and second maturation divisions ..... 474 



425. The testicle with its system of efferent passages . . . 480 



42G. Seminal tubule of a man in transection . . 481 



427. Sertoli cells of the human testis . 482 

 428. Portion of a transection of a seminiferous tubule from the human 



testis, illustrating the various stages in spermatogenesis . . 4s:! 

 429. Successive stages in the metamorphosis of the spermatid into the 



spermatozoon . . . . 484 



430. Diagram of human spermatozoon . . 485 

 431. Spermatozoa of various animals . 486 

 432. Spermatozoa from the semen of man . 487 

 433. Agroupof interstitial cells from the testis of a thirty-five year old negro 488 

 434. Interstitial cells from the human testis . 4v.) 

 435. A small portion of the wall of an efferent ductule of the testicle . 491 

 436. Efferent ductules of the rabbit's epididymis . 491 

 437. Several coils of the rabbit's epididymis in transection . . . 492 

 438. Transection of the ductus deferens of a dog . . 494 

 439. From a section through the wall of a seminal vesicle of man . 4 '.),"> 

 440. Model of a reconstructed prostate gland of man . . 496 

 441. Several alveoli of the human prostate gland, seen in section . 498 

 442. Portion of prostate gland of an old man, showing the prostatic con- 

 cretions ...... . . 499 



443. Prostatic genital corpuscles . . . 500 

 444. Reconstruction of a bulbo-urethral (Cowper's) gland of man . 501 

 445. From a section of the bulbo-urethral (Cowper's) gland of man . 501 

 446. Transection of a child's penis, just back of the glans . . 503 

 447. Helicine artery in section, from the urethral bulb of man . . 504 

 448. The erectile tissue of the penis . . 505 

 449. Section of ovary of adult cat, showing five vesicular (( Ininfian) folli- 

 cles, four with the cumulus oophorus and the enclosed ovum . 508 



