86 Dr. H. Karsten on the Sexual Life of 



apply themselves laterally to the little protuberances (corniculi), 

 whereupon the membrane of the latter at these lateral points 

 becomes pierced through, and the ' Karsten '-cells are transferred 

 through these apertures from the protuberances to the mother- 

 spore-cells. 



" This is the description of the process advanced by Karsten ; 

 and I can only express it as my opinion that the explanation 

 given by that naturalist of this account rests upon a false inter- 

 pretation of what he has seen. 



"An aperture never exists on the sides of the projections*. 

 In the instance figured by Karsten, the protuberance (little horn) 

 is in contact, as happens perhaps as frequently as not, with the 

 mother-spore-cell; but the protuberance is shown to be here 

 quite entire and closed below, and nothing whatever is extruded 

 from it ; in fact, Karsten's figure represents it replete with con- 

 tents, and conveys a more truthful impression than his explana- 

 tion of it." 



Pringsheim in this place copies my figm*e (23 c) ; but he pru- 

 dently omits fig. 23 b, which exhibits the emptied antheridium, 

 and would of itself furnish a contradiction to his denial of my 

 statements f. It has been the fate of Pringsheim himself, who 

 subsequently carried out some researches on the reproduction of 

 CEdogonium, Bulbochcete, and Saprolegnia, to be compelled to 

 confirm my views relative to Vaucheria by analogies which he 

 discovered in Saprolegnia. He, moreover, discovered in Sapro- 

 legnia (supposing Pringsheim's account of his own researches 

 to be more credible than his extracts from the writings of others) 

 a similar double process of reproduction, — in the one case by the 

 intermingling of the heterogeneous contents of two adjoining 

 branches (compare the conjugation and the above delineation of 

 the fertilization of Vaucheina and fig. 23), and, in the second 

 case, a mode of fructification corresponding with that of the 

 higher Cryptogamia, viz. by cells provided with locomotive cilia. 



That the act of fertilization may be accomplished in other 

 Algse allied to Vaucheria by means of cells of larger size, instead 

 of minute cells provided with vibratile cilia, is rendered highly 

 probable fi'om the accounts given by Pringsheim respecting the 

 fructification of CEdogonium, and from what I myself have also re- 

 peatedly noticed. Pringsheim discovers, in these various modes of 



* A pre-existing aperture is certainly never found in this organ, either on 

 its side or at its extremity. No one has ever asserted its existence; and 

 Pringsheim's denial of it is therefore altogether superfluous. If Pringsheim 

 has not seen the absorption of the contiguous cell-walls, it is either because 

 his investigations have not been continued long enough, or because the 

 species of plants examined by him do not present this mode of fertilization. 



t See Boianische Zeitung 1860, p. 385. 



