300 Transactions. 



the primitive stellate or radial form of structure, and one which is not 

 so far removed from it as is the mixed ty^je. Here, along with the 

 plagiotropic habit, branching has become restricted to one plane, so 

 that whereas in the young orthotropic stem the vascular tissues are 

 arranged I'adially, in the mature stem a directive tendency is continually 

 present at the growing apices towards a disposition of the bands of 

 tissue in the plane of branching. 



Jones (13, pp. 31, 32) would connect the epiphytic type of vascular 

 cylinder with that of L. cernuum, Ijut it seems to me from the study of the 

 New Zealand species that the former is rather of the same nature as that 

 of L. Selago. Pritzel's description in Engler and Prantl (9) of L. cernuum 

 and L. laterale as erect-growing tree-like forms without Avidely creeping 

 main axis is obviously incorrect, and his inclusion of L. densum and 

 also of L. voluhile in the section Cernua is open to objection. In her 

 criticism of my former account of the anatomy of six New Zealand species 

 of Lycopodium, Lady Isabel Browne has (5, pp. 224-25) combated the 

 suggestion that the mixed type of L. cernuum is to be regarded as 

 relatively primitive. In this present paper it will be seen that I have 

 accepted this criticism, and now speak of the L. cernuum type as a 

 much modified one. 



General Conclusions. 



It remains now to bring together the main facts and conclusions 

 noted in the different sections of this paper, and to attempt to estimate 

 their value with respect to a natural classification of the genus Lyco- 

 podiuiti, and also to put them into relation with the different theories 

 which have been advanced regarding the interrelationships of the 

 various species. 



The prothalli of seven New Zealand species have been described- — 

 viz., L. Billardieri, L. cernuum, L. laterale, L. voluhile, L. rainulosum, 

 L. fasti gi at um, and L. scariosum — while certain facts concerning the 

 probable nature of that of another species — viz., L. densum — have been 

 given. These prothalli have been found to belong to one or another 

 of the types so well known from the descriptions of Treub, Bruchmann, 

 and others: that of L. Billardieri to the L. Phlegmaria type; those 

 of L. laterale and L. ramulosum to the L. cernuum type; those of 

 L. voluhile and L. fastigiatum to the L. clavatum type; and that 

 of i. scariosum to the L. complanatum type; while we may assume 

 that the prothallus of Jj. densum will be found probably to belong to 

 one or other of the two latter tyjDes. At the same time it has l^een 

 found that interesting modifications are present in all of these New 

 Zealand species of prothalli, such as may have significance in a bio- 

 logical or even in a genetic sense in supjolying connecting-links between 

 the various types. In L. voluhile, L. densum, L. fastigiatum, and 

 L. scariosum it was found that a lai'ge foot is a characteristic feature 

 of the embryogeny, and in L. laterale and L. ramulosum an exceptionally 

 large and long-lived protocorm has been described. Tlie conclusion was 

 reached from the study of its development that the large size of this latter 

 organ in these two species is merely a physiological adaptation, and that 

 this suggests that a similar interpretation is to be applied in the cases of 

 the other species in w^hich the protocorm is found. It was seen that a 

 stellate or radial configui-ation of the vascular cylinder is characteristic in 

 L. Selago, L. Billardieri, and L. varium ; a mixed type in L. cernuum^ 



