HoLLOWAT. — Six New Zealand Species of Lycbpodium. 357 



clay banks. The prothallus grows at the surface of the grouud, is very 

 small, delicate, and short-lived. In the case of L. laterale prothallial plants 

 were found in two localities, growing on recently overturned marshy soil. 

 The prothallus of this species corresponds to the type of L. cernuum, and is 

 small and short-lived, and situated at the surface of the ground. Prothalli 

 of L. Billardieri were found growing in a collection of humus on a bush 

 tree, young plants being collected from several such localities. The 

 prothalli are destitute of chlorophyll, are much branched, and grow beneath 

 the surface of the soil. They are long-lived ; in some cases young plants 

 an inch or more in height, and bearing three well-developed leaves, were 

 observed with healthy prothalli still attached to them. The prothalli seen 

 ranged from 1-12 mm. in total length. The prothallus of this species appears 

 to correspond to the L. phlegmami type. Prothallial plants of L. volubile 

 were found in three distinct localities. The prothallus is large, firm, and 

 long-lived. Healthy prothalli were seen still attached to plants which were 

 as much as 10 cm. in length. Generally the prothalli are subterranean, 

 being buried from 1-4 cm. in depth ; in several instances, however, they 

 were observed growing at the surface of the ground, and the upper portion 

 of the prothallus was then well supplied with chlorophyll. The prothallus 

 of L. scariosum was discovered in two localities. Like that of L. volubile, it 

 appears to correspond to the L. clavatuni type. It is large, firm, and long- 

 lived, and in every case was found deeply buried (from 2-6 cm.). Long- 

 continued search was made for the prothalli of L. densum in many localities, 

 but without success. One young plant, however, was discovered, on 

 which, as in the case of the young plants of L. volubile and L. scariosum, 

 there was a large persisting " foot " situate at a point on the stem some 

 distance below the surface of the ground. We may accordingly conclude 

 that the prothallus of this species is large, firm, and long-lived. 



Early Embryonic Stages. 



No minute study of the prothalli of the above-mentioned species was 

 made, so that the early embryonic stages of the young plants were not 

 observed. 



Protocorm. 



The young plants of L. cernuum and L. laterale both possess this organ. 

 This is so well known in the case of L. cernuum. that it will not be necessary 

 to give any detailed accoiint of it here, so far as this species is concerned. 

 The protocormous structure in the young plant of L. laterale, however, 

 would seem to afford such interesting material for the discussion of the 

 significance of this organ that an account of its development in this species 

 will now be given. The first stages in the development of the protocorm 

 of L. laterale correspond closely to what takes place in L. cernuum. The 

 subsequent stages are, however, peculiar : Instead of a stem apex being 

 differentiated at a comparatively early stage, as in L. cernuum, its develop- 

 ment is postponed for a considerable time ; and, instead, the protocorm 

 grows greatly, and elongates sideways as a rhizomatous structure, bearing 

 numerous protophylls along its dorsal surface (Plate XXXI, fig. 5). This 

 " rhizome " is composed entirely of parenchymatous cells, in which starch 

 and water are stored ; numerous rhizoids arise from its ventral surface. 

 The " rhizomes " shown in Plate XXXI, figs. 7 and 8, had attained a 

 length of 1 cm. and a thickness of from 2-3 mm. ; that shown in fig. 8 

 had branched. Eventually the protophylls aggregate at some point on the 



