













320 



DK. M. T. MASTERS Otf THE MOBPHOLOGY, 



over, these two leaves are concrescent at the base bo as to form a shallow 

 cup from the outer side of which, a little above its base, emerge, as has been 

 said, the two leaves constituting the pair immediately beneath and which 

 have probably been uplifted by the vigorous basal growth of their larger 

 neighbours. 



The leaves of the sixth pair are median, and this time it is the posterior 

 of the two which is the larger, whilst the smaller anterior one is uplifted 

 with the base of its neighbour and with it forms a shallow cup. The next 

 two leaves are lateral and slightly unequal ; the next succeeding, eighth 

 pair is median, and of these the anterior leaf is the larger. 



Between the third and fourth pairs of leaves the internode is rather 

 more lengthened than between the other pairs, and this allows of the sepa- 

 ration as a " gemma" of the upper portion of the bud. 



This description from living specimens differs somewhat from that of 

 Newman, and is introduced here with the view of inducing future obser- 

 vation as to whether there is anything more than superficial resemblance 

 between these buds and the adventitious ones that are formed in some pro- 

 liferous cones. ' ' 



Goebel describes the formation o[ buds or shoots in Isoetes at the position 

 on the leaf where a sporangium is usually found, and this shoot separates 

 from the mother-plant and develops into a new plant, as in the case of 

 the Lycopodium just mentioned. 



In both these instances the formation of adventitious buds seems, like 

 that in the prolified cones, to be due rather to substitution than to any 

 actual metamorphosis of the sporangium, or even of the axis bearing it. 









i 







Parlatore * describes and figures a cone of Pinus Lemoniana 

 in which the lower scales are changed into branches with leaves, 

 and a cone of Abies Brunoniana affected in a similar manner. 



In Sequoia gigantea M. Carriere has figured a cone with both 

 leafy and axillary prolification t. 



The proliferous cones of Sciadopitys are of great interest (figs. 26 

 and 27). In the ordinary cones of this plant the bracts are nearly 

 completely concrescent with the fruit-scale, but in the specimen in 

 question the bracts and the fruit-scale are more or less detached 

 one from the other. Moreover, the bracts gradually assume the con- 

 dition of the perula) such as surround the buds. In this plant, 

 then, the bracts, in place of becoming more leafy, as they do usually 

 in proliferous cones, revert to the vaginal or perular condition. The 

 im'tamorphosis is in this case retrograde instead of progressive, 

 or, to speak more correctly, development has been arrested instead 

 of enhanced. From the axil of each of these perulse proceeds a 









■ 



' 



, 

















* Parlatore, Studi Organografice delle Conifere (1864), p. 35 

 t Carriere in Revue Horticole (1887), p. 509, fig. 103. 











«~ 







. 

























■ 































\ 



