1 90 MORPHOLOGY. 



It appears to me, that the Lycopodia are most nearly allied to Mosses 

 and Liverworts, from the little we as yet actually know of the history of 

 their entire morphological development.* Isoetes may constitute a sepa- 

 rate family allied to these, or, still better perhaps, be reckoned as 

 belonging to them ; at any rate, a moderately exact comparison will 

 suffice to show that this plant does not belong to the Rhizocarpece, and 

 that it cannot either constitute a transition stage from any immediately 

 approximate family to the Rhizocarpece. The only resemblance that 

 has led to their being placed together was the circumstance that, in 

 both, the reproductive organs were situated below. (With equal justice 

 Raja Pastinaca and the Scorpion might be brought into the same family, 

 since both have a sting in the tail.) But, as the statement was once 

 printed, it availed little that more exact observations showed Isoetes to 

 be devoid of any analogous characteristics, or even the most remote re- 

 semblance to the Rhizocarpece; DeCandolle alone appears to have had 

 more correct views on the subject. Linkf, a few years ago, again coupled 

 the two together, invita natura* 



105. A. At the base of the leaves (which are sometimes com- 

 pressed into a kind of club at the extremity of an extended leafy 

 stem, and assume somewhat different forms), or more rarely in an 

 indentation of the leaves (for instance, Tmesipteris\ there arises a 

 cellular knob, whose external layers of cells become the wall of the 

 sporocarp, and whose inner cells, as parent cells (sporangia), 

 generate four spores each, invested with a peculiar membrane, 

 which seldom exhibits warts or points, after which the sporangia 

 become absorbed. In the Bernhardice the sporocarps are placed 

 upon the points of the shoots, two or three grown together. The 

 ripe sporocarp is round, kidney or crescent shaped, and tears with 

 a vertical cleft (as in Lycopodium annotinum), or a horizontal one 

 (L. inundatum), the margins of which are often lobed, (as in L. cana- 

 liculatum). In Isoetes the sporocarps are somewhat immersed in 

 the base of the leaf, and covered by a heart-shaped scale. They 

 contain, among obliquely directed cellular filaments, small cellular 

 sacs, with many small spores exhibiting the ordinary formation, 

 and other sacs which enclose four larger spores, consisting of cells 

 provided with the ordinary integument, and having a thick crust 

 of carbonate of lime (?). 



Mohlf has proved, as incontrovertibly as it was possible without 



* The interesting experiments on the germination of the larger spores were 

 pursued by Bischoff, and first made known by him ; notwithstanding which, he says 

 (Die kryptogamischen Gewiichse, p. 97.)> " We find no distinctly separated main 

 roots in the Lycopodia," because he had only the old developed plant in view. This is 

 certainly a remarkable illustration of the extent to which this routine-like method in 

 science may blind the eyes of people even against their own discoveries. 



See Filicum Species in Horto Ilegio Botanico Berol., Berlin, 1841 ; a work which 

 is twenty years behind the discoveries made in all things relating to general science. 



( Mohl, Ueber die morphologische Bedeutung der Sporangien der mit Gefiissen 

 versehenen Kryptogamen, Tubingen, 1837, p. 28. 



