M. Miiller on the Development of the Lycopodiaceae. 117 



vertex of the ellipsoid, this vertex appears somewhat depressed 

 inward as if emarginate (fig. 12 fl fl). If it is then looked at 

 again on the side which brings the long face [c d in fig. 10) 

 across the eye, the long side appears as a rounded trigone 

 (fig. 11 « 6 is the other side lying behind). In all these forms 

 the oophoridium can externally only be made out to be a vesi- 

 cular projecting organ, and naturally so, since the four spores 

 have not yet become developed into compact masses. In pro- 

 portion as the spores are perfected it appears to become gradually 

 denser until it acquires the above-described four-lobed shape. 



Here, before we know anything of the interior of the oopho- 

 ridium, the question proposes itself. What is the oophoridium 

 actually ? According to all that I have hitherto said about it, 

 the oophoridium is the whole, metamorphosed terminal bud of a 

 main axis. It is therefore an axial organ. 



Most important grounds support this opinion. The first is 

 the independent position of the oophoridium, opposite the spike, 

 in the early condition (fig. 6 a). Here we distinctly see the 

 oophoridium and spikelet are the two metamorphosed branches into 

 which a main branch has just divided. In a later condition it 

 does certainly appear as if both oophoridium and spikelet be- 

 longed to one single axis. There can however be so little doubt 

 about our having to do with two branches, that in the absence 

 of other argument, this mode of development alone would be 

 sufficient to warrant my opinion. All that a branch possesses is 

 found with the oophoridium, since we have already seen above 

 that it is protected by two leaves ; and these two intermediate 

 leaves are to be regarded as the two first of that which is here 

 developed into an oophoridium. We also saw above, that near 

 the oophoridium and the spike is often produced the same root 

 which appears in the bifurcation of a main axis. Moreover that 

 in L. denticulatum, as in most of the Selaginellce, only one 

 oophoridium is found on each fruit-bearing axis, speaks equally 

 in favour of my view, since it stands in exact connexion with the 

 scattered fructification of the said axis. The branches divide 

 too frequently in L. denticulatum for the branch to produce 

 many fruits. It is too thin to form a main axis out of which 

 oophoridia might be developed. The case is different in L. se- 

 laginoides. Here the axis of the fruit is very thick, and thus 

 it is suited to form branches which may develope into oopho- 

 ridia. Another proof is, that in the young condition the 

 oophoridia are all compressed, as the branch of L. denticulatum 

 always is, since the oophoridium is in fact only the transformed 

 apex of the branch. The internal course of the vascular bundle 

 is even a better evidence, for a vascular bundle runs into the 

 pedicel of the oophoridium (fig. 14), a condition which must be 



