HoLLOWAT. — Studies in the New Zealand Species of Lycopodium. 263 



and branches being subterranean, while at frequent intervals large 

 adventitious roots are borne. It is in the epiphytic species that this 

 character of extensive vegetative propagation is noticeably absent, and 

 there, of course, the opportunity is wanting owing to the confined area 

 in which the plants grow. The usual habitats of most of the terrestrial 

 species are not suitable for the germination of the spores. Such forms 

 as L. densurn, L. fastigiatum, L. voluhile* and L. scariosum luxuriate 

 in open situations which are dry and unpromising. L. cernuum, 

 L. laterale, L. ramidosum, and L. Drummondil also grow most abund- 

 antly in peaty sour land which is alternately waterlogged or dried up, or 

 even permanently wet. From my own observations, extended over a good 

 number of years and in many parts of New Zealand, I have found it to 

 be an almost invariable rule that young plants and prothalli are not to be 

 met with in localities in which the adult plants are abundant. It is only 

 in special localities, such as a damp shaded clay bank or roadside cutting, 

 or some other patch of recently disturbed soil in the neighbourhood of 

 adult plants, that the young plants occur. But it must be added that 

 when the favourable conditions are present prothalli occur often in great 

 abundance. In the case of several of the above-mentioned New Zealand 

 species, prothalli and young plants were found in several localities in 

 different years, while in certain species, as, for example, in L. cernuum, 

 L. fast'gwfiun, L. volubile, and L. scariosiim, they were discovered in 

 large numbers. Bruchmann (6, p. 5) records that when once he had dis- 

 covered the right kind of locality he was able to collect over five hundred 

 prothalli of each of the species L. clavcitum and L. annofinum. The 

 ej^iphytic species grow under conditions which are normally more favour- 

 able to tlie development of the prothallus — -namely, in shaded, damp, well- 

 drained patches of humus. Treub (17) was able to find the prothallus of 

 four different epiphj^tic species. Neither Miss Edgerley nor the present 

 writer exjDerienced great difficulty in discovering the prothallus of L. Bil- 

 la^rdieri. It is certain that in the case of some of the species — for 

 example, L. faatigiatum, L. scanosum, and L. volubile — a long period 

 of time, with consistently favourable conditions, is required before the 

 prothalli are fully grown and the young plants are established. It has 

 been shown above that there is reason to believe that a period of fifteen 

 years may elapse before the spores of L. fastigiatum have germinated 

 and the prothalli have developed. This is very similar to the conclusion 

 reached by Bruchmann (6, p. 10) in those instances in which data to Avork 

 upon were forthcoming. It woidd seem, however, that the prothalli of 

 such species as L. cernuum, L. ramulosum, and L. laterale, which are 

 exceeding minute and delicate, require only a single season for their full 

 development. These are the species which occur in a typically damp 

 habitat. However, Avhen the prothalli, and even also the young plants of 

 terrestrial species, have succeeded in developing, a change of conditions, 

 as, for example, a more than usually dry summer, may restdt in the 

 destruction of all the j-oung plants and of the prothalli also. Thus we 

 conclude that although the spores of the Lycoyoditmi species germinate 

 freely under suitable conditions, yet the long period of the growth of 

 their prothalli and young j^lants, and the uncertain conditions under 

 which they live, have brought it about that the Lycopodiums have to 

 depend mainly tipon the vegetative mode of propagation. Probably we 

 may also conclude that in the case of the terrestrial species propagation 



* 111 parts of Westland, which possesses a wet climate, there are large breadths of this 

 species where road cuttings have been made. 



