SEMEN. 



483 



tozoa do not stretch but remain wrapped up. The spermatozoa of Scymnus nicesensis (fig. 

 It is a remarkable sight to see the cyst burst- 349. A) are similar but rather longer, whilst 



Fig. 345. 



A. bundle of Spermatozoa of Pelobates. 



ing on being treated with water. The whole 

 mass of spermatozoa suddenly bursts forth, 

 and only remain attached to each other by the 

 heads, as if imbedded in one common sub- 

 stance. The separate fibres radiate in all direc- 

 tions, each being wrapped up in a spiral form. 

 FISHES. In the class of fishes, the sper- 

 matozoa occur in two forms. The first is 

 found throughout the osseous fishes, and 

 also in Amphioxus. The other form is found 

 among the Piagiostomes. In the former case 

 the spermatozoa consist (fig- 346.) of a 

 very small globular body (of -^o'" ^TTO'"* 

 or even smaller, down to T^OT/" as m Pcrca 

 fluviatilis), and an extraordinarily thin, hair- 



Fig. 346. Fig. 347. 



Spermatozoa of Perca Spermatozoa of Colitis 

 Jluviatilis. fossilis. 



like tail, which, however, possesses compa- 

 ratively a very considerable length. Sometimes 

 the body at the point of insertion of the tail 

 has a small knotty appendix, as in Cobitis 

 (fig. 347.), which gives to it a pear-like shape. 

 The body in some genera is so small that it 

 can hardly be perceived with any distinctness. 

 This also applies to the spermatozoa of 

 Fin 348 Petromyzon, in which the form of 

 ' the body is, however, different. In 

 P. marinus* the body is egg-shaped; 

 in P. fluviatilis (fig. 348.) staff- 

 shaped. The length of the body in 

 P. fluviatilis is TST/"* 



The spermatozoa among the Pla- 

 giostome fishes are similarly formed 

 Spermato- to those of the birds. They are long, 

 zoon of filiform, and furnished with an an- 

 Petromy- terior cy ii nc i r i ca i body. In Scyllium 

 tilis a ~ Caniculathe body is' stiff and quite 

 straight, and tapers at both ends. 

 The tail is thin, and of an equal length to the 



* J. Muller, TJntersuch. uber zu Eingewerde der 

 Fische, Berl. 1845, S. 6. 



. 349. 



A. Spermatozoa of 

 Scymnus nicecensis. 



B. Spermatozoon of 

 Torpedo Narce. 



the body, instead of being straight, describes 

 two long spiral windings. Four more narrow 

 spiral windings are found round the body of 

 the spermatozoa in Spinera acanthias, which 

 measures ^V"* whilst the length of the whole 

 spermatozoon amounts to iV" A similar num- 

 ber of spiral twistings are likewise seen in the 

 body of the spermatozoa of most of the rays, in 

 Torpedo narce (fig. 349. B), Raja rubus, &c. 

 In Raja oxyrhynchus it is only the anterior 

 part of the body which is spirally wound in a 

 length of about eV", whilst the posterior part 

 is straight. The number of the windings is 

 nevertheless, however, more considerable, viz. 

 7 or 8. The length of the whole spermatozoon 

 amounts to -J/". Chimera monstrosa like- 

 wise exhibits these windings, notwithstanding 

 the comparatively short body ( T ^ /x/ ) of its 

 spermatozoa, which have a length of %" 

 The number of windings is three. 



The developement of the spermatozoa in 

 fishes has as yet only been observed in the 

 Plagiostomes. It is exactly the same as in 

 frogs and birds, as the statements ofHallmann* 

 lead us to infer. Almost all of the sperma- 

 tozoa are united with one another in bundles. 

 According to our researches in Torpedo 

 Narce, the spermatozoa are produced sepa- 



Fig. 350. 



Cysts, with developing cells from the testicle of 

 Torpedo Narce. 



rately in the cells of developement, which pos- 

 sess about the size of o-W, and which are 



Muller's Archiv., 1840, S. 467. 

 i I 2 



