SPERMATOZOA. 



847 



Fig. 635. 

 Crystals from spermatic fluid. 



of the bull (G. Retzius). These consist of a flattened, long, narrow, transparent, proto- 

 plasmic mass, with a fibre composed of many delicate threads in both margins. At the tip 

 of the tail both fibres unite into one. The fibre of the one margin is generally straight 

 the other is thrown into wave-like folds, or 

 winds in a spiral manner round the other 

 (W. Krause, Gibbes). G. Retzius describes a 

 special terminal filament (fig. 636, e). An 

 axial thread surrounded by an envelope of 

 protoplasm, traverses the middle piece and 

 the tail (Eimer, v. Braun). [Leydig showed 

 that in the salamander there is a delicate mem- 

 brane attached to the tail, and Gibbes has 

 described a spiral thread attached to the head 

 (newt) and connected with the middle piece 

 by a hyaline membrane.] 



Motion of the Spermatozoa. [After the 

 discharge of the seminal fluid, the spermatozoa 

 exhibit spontaneous movements for many 

 hours or days.] The movements are due to 

 the lashing movements of the tail, which 

 moves in a circle or rotates on its long axis, 

 the impulse to movement proceeding from 

 the protoplasm of the middle piece and the 

 tail, which seem to be capable of moving when 

 they are detached (Eimer). These move- 

 ments are comparable to those that occur in 

 cilia ( 292), and there are transition forms 

 between ciliary and amoeboid movements, as in the Monera. Reagents. Within the testis 

 they do not exhibit movement, as the fluid is not sufficiently dilute to permit them to move. 

 Their movements are specially lively in the normal secretion of the female sexual organs 

 (Bischoff), and they move pretty freely, and for a long time, in all normal animal secretions 

 except saliva. Their movements are paralysed by water, alcohol, ether, chloroform, creosote, 

 gum, dextrin, vegetable mucin, syrup of grape-sugar, or very alkaline or acid uterine or vaginal 

 mucus (Donne), acids and metallic salts, and a too high or too low temperature. The narcotics, 

 as long as they are chemically indifferent, behave as indifferent fluids, and so do medium solu- 

 tions of urea, sugar, albumin, common salt, glycerin, amygdalin, &c. ; but if these be too dilute 

 or too concentrated, they alter the amount of water in the spermatozoa and paralyse them. 

 The quiescence produced byt water may be set aside by dilute alkalies (Virchow), as with cilia 

 (p. 452). Engelmann finds that minute traces of acids, alcohol, and ether excite movements. 

 The spermatozoa of the frog maybe frozen four times in succession without killing them. They 

 bear a heat of 4375 C., and they will live for 70 days when placed in the abdominal cavity of 

 another frog (Mantegazza). 



Resistance. Owing to the large amounts of earthy salts which they contain, when dried 

 upon a microscopical slide, they still retain their form (Valentin). Their form is not destroyed 

 by nitric, sulphuric, hydrochloric, or boiling acetic acid, or by caustic alkalies ; solutions of 

 NaCl and saltpetre (10 to 15 per cent.) change them into amorphous masses. Their organic 

 basis resembles the semi-solid albumin of epithelium. 



Seminal fluid, besides spermatozoa, also contains seminal cells, a few epithelial cells from the 

 seminal passages, numerous lecithin granules, stratified amyloid bodies (inconstant), granular 

 yellow pigment, especially in old age, leucocytes, and sperma crystals (Fiirbinger). 



Development of Spermatozoa. The walls of the seminal tubules, n, which are 

 made up of spindle-shaped cells, are lined by a nucleated, protoplasmic layer (fig. 

 637, I, b, and IV, h), from which there project into the lumen of the tube long 

 (0*053 mm.) column-like prolongations (I, c, and II, III, IV), which break up at 

 their free end into several round or oval lobules (II.) the spermatoblasts 

 {v. Elmer) ; these consist of soft finely granular protoplasm, and usually have an 

 oval nucleus in their lower part. During development, each lobule of the sper- 

 matoblast elongates into a tail (IV, r), while the deeper part forms the head and 

 middle pieces of the future spermatozoon (IV, k). At this stage the spermatoblast 

 is like a greatly enlarged, irregular, cylindrical epithelial cell. When development 

 is complete, the head and middle piece are detached (III, t), and ultimately the 

 remaining part of the spermatoblast undergoes fatty degeneration. Not unfre- 

 quently in spermatozoa we may observe a small mass of protoplasm adhering to the 



