92 Transactions. 



Conclusions. 



Vegetative reproduction is a common phenomenon in the Lycopodiaceae, 

 as it is well known to be also in the Mosses, and it may take place in a 

 great variety of ways. It is noteworthy that the swollen tuberous basal 

 region termed the " protocorm " by Treub in the case of the sexually pro- 

 duced plants of L. cemuum is present also in the adventitious plantlets 

 of L. cemuum, and in all the plantlets of L. laterale and L. ramulosum 

 whether produced sexually or adventitiously. In no case in any of these 

 three species have I ever noticed the presence of fungal hyphae in the cells 

 of the " protocorm," although Goebel (1905, p. 233) says that a fungus 

 infection occurs in the root tubers of L. cemuum and in certain swellings 

 on the stem of L. inundation, and that it there appears to promote an 

 increase of plastic material. In all the cases of protocormous swelling 

 examined by me I have never been able to discover more than abundant 

 protoplasm and starch-grains, and have concluded that the swelling acts 

 mainly as a storage region, although it must be added rhizoids are always 

 developed early on the tubers, and in some cases also these rhizoids 

 show the presence of starch-grains. A swollen area comparable to the 



' protocorm " occurs sometimes on detached leaves of L. ramulosum, in 

 conjunction with the formation on the leaf of an adventitious bud ; and 

 also the plantlets which are developed adventitiously from cortical cells in 

 the roots of the same species begin as kt protocorms " more or less regularly 

 formed. Plantlets formed vegetatively as outgrowths from the protocormous 

 rhizome of the sexually produced plantlets of L. ramulosum also begin as 

 tubers. It may not be out of place also to add to this list of vegetatively 

 produced " protocorms ; ' the annually produced tuber in Phylloglossum 

 which is the first stage in the development of the new plant. Here also 

 the tuber acts as a storage tissue. 



It is instructive to compare the Lycopod " protocorm " or bulbil with the 

 flat or sometimes solid gemma of the Hepaticae, and with the filamentous 

 protonema which in the Musci precedes the formation of vegetatively pro- 

 duced plantlets. They may be compared in the light of being a response 

 made by the plants belonging to those different classes to certain external 

 conditions. Klebs' well-known experiments in the Algae and Fungi have 

 shown that sexual or vegetative reproduction may be respectively induced 

 by varying the conditions of light, water, and food under which the plants 

 are growing. This may well be a natural phenomenon also in the case of 

 the Hepatics and Mosses, or even of the Lycopodiaceae and other pterido- 

 phytes. It is possible, that in the Lycopodiums the vegetative tuber or 

 " protocorm " is to be regarded as a resting body designed to withstand a dry 

 season. If this can be accepted as a possible explanation in the case of 

 the vegetatively produced plantlets, there is a strong suggestion that the 

 same interpretation should be applied to the case of the first - formed 



' protocorm " in the sexually produced plants of the species of the cemuum 

 type. The tuber of the vegetatively produced plant is similar in appear- 

 ance and function to that of the sexually produced plant, and the origin 

 from it of the protophylls, stem-axis, and first root is also identical. Thus 

 the study of the protocormous tuber in the three New Zealand species 

 L. cemuum, L. ramulosum, and L. laterale suggests that in all its forms it 

 is to be regarded as a vegetative adaptation characteristic of certain sections 

 of the Lycopodiaceae, rather than as the persisting rudiment of a highly 

 primitive organ. 



