1 24 Mr Thomas A. Huxley on a Hermaphrodite and 



I may mention here that ciliated organs, possibly homologous 

 with these, and with the lateral convoluted canals of the 

 Lumbricidce and Hirudinidm are by no means uncommon 

 among the Annelida Errantia, and may be observed in 

 Phyllodoce ; it requires care however to discover them. 



Nervous system. — On this head the result of my examina- 

 tions was exceedingly unsatisfactory, as I could assure myself 

 of the existence of only two oval ganglia, one on each side of 

 the oesophagus, each of which presented a dark pigment mass 

 (eyespot ?) on its anterior extremity. 



Reproductive elements. — Protula Dysteri can hardly be said 

 to possess special reproductive organs, the reproductive ele- 

 ments, viz., ova and spermatozoa, being developed as it were 

 accidentally from the walls of the perivisceral cavity, by the 

 fluid contained in which (whose nature and importance M. de 

 Quatrefages has so well pointed out) they are bathed, and 

 supplied with nutritive materials. It appeared to me that the 

 spermatozoa or ova took their origin in granular thickenings 

 of that portion of the face of the dissepiments which is 

 traversed by the transverse vessel, becoming detached thence, 

 and floating freely in the perivisceral fluid, as they attained 

 their full development. * 



The youngest spermatozoa were minute spherules, of not 

 more than ^oV o °f an i ncn i* 1 diameter, aggregated together 

 into irregular masses (fig. 11). In a more advanced state a very 

 fine short and delicate filament could be observed springing from 

 one side of this body. By degrees the spherule became ellip- 

 tical, and narrowing pari passu with the elongation and thick- 

 ening of the filament, the ultimate result was a spermatozoon, 

 such as that represented in fig. 11, with a subcylindrical 

 slightly pointed head of 3 £$ -$ of an inch in diameter, and a 

 very long actively-undulating tail. 



The ova are, at first, very small, not more than j^o 0- of an 

 inch in diameter, and possess a relatively very large, clear 

 space, representing the germinal vesicles, containing a minute 



* Frey and Leuckart (Zool. Untersuchungen, p. 88) assert that the genera- 

 tive elements of the annelids are developed from a free Diastema, and not from 

 the septa only, as Krohn asserts to be the case in Alciope, and as I should, 

 from what is stated above, be disposed to believe. 



