36S Robinson : Propagative Buds of Malaxis paludosa. 



body was sometimes more elongated, the basal portion being 

 separated from the upper b}^ a shght constriction [cf. fig. 7). 

 Presumably these basal cells serve as a kind of haustorium or 

 absorptive organ. Active division was seen in progress, both 

 in nuclei of the cells of the central bod}^ and of the outer 

 envelope. The number of chromosomes estimated was twenty. 



B3' the division of some of the peripheral cells of the central 

 bod}', new enveloping leaves originated, and in some cases 

 (fig. 7) at this stage the interior portion had outstripped the 

 gro\\i:h of the original envelope. Even now the basal 

 haustorial region of the central body was clearly distinguished, 

 it ha\d.ng enlarged somewhat. A later stage still (fig. 8), 

 shewed conclusively the nature of the envelope, for here, two 

 pairs of enveloping leaves, clearly alternate, surrounded an 

 activeh' dividing vegetative apex. Further, in this case the 

 apical portion of all four leaves was very evidently meristematic, 

 and in active division. This is an important fact, for it gives 

 the clue to the ultimate origin of these vegetative buds on the 

 apical regions of the leaves. This origin is rendered possible 

 bj' the cells of the apical region of the leaf retaining their 

 meristematic activit}' after unfolding. In the stage seen in 

 fig. 8, the basal region was not now^ recognisable. 



The mesophyll cells underlying the developing buds (fig. 5 c) , 

 were very large, and more rounded than the ordinary cells of 

 the mesophyll. They had extremely large nuclei, and distinct 

 nucleoli, as well as dense, protoplasmic contents. These 

 probably play an important part in the nutrition of the growing 

 buds. Vascular strands w^ere not observed to reach tissue just 

 below the buds. 



Kerner {a) has remarked that these buds are singularly 

 like seeds in external appearance ; but he goes on to say, they 

 merely give rise to tubers on germination. The resemblance 

 of the developing buds to the developing embryos of various 

 monocotyledons is very remarkable. The morphological 

 resemblance is probably a mere analogy, but does not seem to me 

 to be altogether surprising in view of the fact that both embr^'o 

 and propagative bud, though of widely different origin, serve 

 the same biological function — the propagation of the species. 



In the Pteridophytes, Bower [h] remarks on a like striking 

 similarity between the tuher of Phjiloglossum, which provides 

 for its yearly growth, and the embryo of the same plant. 



Further, whilst lacking the stimulus and advantages of 

 fertihsation, the sporophytic buds, as we must regard these 



