358 LYCOPODIALES 
first year’s growth. From the description of Thomas it thus appears that 
the embryology is just what would be expected of a plant which had 
already been recognised as repeating in its annual cycle a development 
similar to that of ZL. cernuum. 
The yearly growth of Fy/loglossum resembles in many features that 
of the embryo: it originates at the apex of the storage-tuber formed 
during the preceding year, and its punctum vegetationis retains its identity 
as the centre of the new growth. Sometimes only a single leaf is formed, 
Fic. 188. 
A and #& embryos of Lycopodium cernuum, showing protocorm. s=suspensor; 
p=foot; cot=cotyledon; /', £2, etc.=successive leaves; r=root; wl=punctum 
wegetationis. X35. (After ‘l'reub.) 
but usually several more in strong plants: they arise in succession laterally 
around the apex, but are definite neither in number nor in position. In: 
those cases where the plant does not form a strobilus, the apex, which 
lies centrally among the leaves, becomes depressed, while the tissue 
surrounding it, continuing to grow actively but unequally, a process is 
formed which develops into the new tuber (Fig. 189 a, B). Where a 
strobilus is formed it arises directly from the apex (Fig. 189 c, D, E), and 
a new provision has to be made for the formation of the new tuber. 
This appears adventitiously at the base of the peduncle, as a depression 
which is carried outwards on an elongating process due to active and 
