456 Mr. A. Henfrey on the Reproduction of the 



find the prothallium, as in Spharocarpus and Antkoceros, reduced 

 to a cellular structure little more complex than the prothallium 

 of a Fern, which affords a link connecting it with that of Sela- 

 ginella, &c, and so with the endospermous tissue of the Gym- 

 nosperms. 



Finally, in the Characese we seem to meet with a group re- 

 duced to a prothallium, bearing archegonia {nucules) and anthe- 

 ridia {globules), in which the sole result of fertilization is the 

 development of a new prothallium from the central cell of the 

 archegonium, no spore-bearing form coming to light ; and thus 

 we get the opposite extremity of the scale, at the head of which 

 stand the Angiospermous flowering plants where the spore- 

 producing form alone is represented, since the formation of 

 the endosperm-cells in the embryo-sac before fertilization only 

 affords the most distant trace of its analogy to the prothallia of 

 the Cryptogams, an analogy which is only rendered clear by the 

 interposition of the Gymnosperms where this endosperm exhi- 

 bits so many characters relating it to the prothallium of Selagi- 

 nella, &c. 



The following is a tabular view of the conditions which pre- 

 sent themselves more or less distinctly in the Phanerogamia and 

 higher Cryptogamia. 



The column marked Embryonic Form shows the growth or 

 increase taking place in the embryonal vesicle or germ-cell pre- 

 viously to its development into the new plant or plants of the 

 vegetative form. Where the is placed it signifies that the em- 

 bryonal cell of the archegonium becomes directly developed into 

 one new plant of the vegetative form. 



The placed in the column of the vegetative system of the 

 Hepaticse and Musci indicates the absence of this, since the im- 

 pregnation results in the growth of the sporangium, which re- 

 mains attached to the persistent vegetative organs of the sexual 

 form. 



[The bud-like nature of the production of the spores in the 

 higher Cryptogams is strongly indicated in a monstrous specimen 

 of Eucamptodon perichcetialis, Mont., described in the Annals of 

 Nat. Hist. vol. xvi. p. 354, by Dr. Montagne, where the sporangia 

 were filled with gemma like those of Liverworts, in the place of 

 spores.] 



