HoLLOWAT. — Studies in the New Zealand SjJecies of Lycopodiuin. 271 



uppermost fungal region being situated immediately below it. In 

 figs. 32b and 32f ai-e shown two solid massive protlialli. The latter of 

 these was 2|- mm. in total height, and about 2 mm. in diameter in its 

 upper region. Tliese prothalli (and the other four of the same nature 

 which were found) seem to correspond to the upper bulky region of the 

 long-drawn-out prothallus of this species, described above. It would 

 appear, however, that ihey owe their compact form not to the decaying- 

 away of the shaft, but to its almost complete suppression. That this is 

 so is evident from fig. 32f, which shows the first-formed region of the 

 prothallus in a remarkably intact condition. Fig. 32g is a much- 

 enlarged view of the same. These short stout prothalli were in three 

 instances found attached to young plants which bore four or five proto- 

 phylls. Half-decayed prothalli were observed attached to young plants 

 of still greater size and age. All the prothalli of L. ranndosum were 

 green in their upper region and in the upper parts of the shaft. After 

 studying the prothallus of this species I carefully examined again serial 

 sections of several prothalli of L. cernuum, and in the case of one of 

 them found that the primary tubercle was continued below into such a 

 filamentous process as that shown at the base of the prothallus in fig. 32b. 

 I am inclined also to regard the club-shaped process described on the 

 primary tubercle of two of the prothalli of L. laterale, and illustrated 

 in fig. 16, as corresponding to the first-formed region of the prothallus 

 of L. ramidostim. "It would seem thus that in tliese species, in some 

 instances at least, and perhaps also as a rule, the spore on germinating 

 gives rise to a delicate filament of cells which at some point or other 

 soon becomes infected Avith the fungal element and then swells to form 

 the so-called " primary tubercle." One prothallus found was shaped 

 like the letter Y, it having branched into two more or less equal branches 

 about half-way up the main shaft. At the point of branching the 

 shaft was swollen and showed a fungal area, there being also the usual 

 " primary tubercle" at the base of the shaft. 



The prothallus of L. ramidosum presents some important features which 

 serve to emphasize the great variability of the Lycopodium prothallus, 

 and which suggest links between the different prothallial types much in 

 the same way that the variations in form of the prothallus of L. Selago 

 have been interpreted by Lang (14, pp. 303-5). The form with the long- 

 shaft and scattered fungal areas indicates how the long-drawn-out 

 prothallus of L. Selago, and so also the epiphytic type of prothallus, 

 could have arisen from an ancestral L. cer?iu inn -like type; and, on the 

 other hand, the short massive prothallus of L. ramidosum, with its 

 longer life and greater capability of the horizontal extension of its 

 upper region, is intermediate in form between the L. cernuum type and 

 the short variety of the L. Sel-ago prothallus, and is suggestive of the 

 subterranean L. clavafum and L. complanotum, types. 



L. fastigiatum. 



The general form of this prothallus in the mature state would seem 

 to be very like that of L. volubile, but there is an important develop- 

 mental distinction to be noted. Figs. 33-40 illustrate specimens in 

 which the manner of development of the adult form can be traced. The 

 youngest prothalli found were about J mm. in height. They showed, a 

 rounded tubercular opaque body surmounted by a smaller and more 

 translucent region. Fig. 33 is that of a young prothallus 1 mm. in 

 height showing these two regions. Very early in the development the 



