179 
Helminthostachys zeylanica. 
ated from the amitotic division of one or more mother-nuclei. The 
occurrence of constricted nuclei, such as I have represented in Fig. 2, bears 
out this view. Neither here, nor at any subsequent stage, have I seen 
tapetal nuclei dividing by mitosis. 
The tapetal cytoplasm at this stage contains a quantity of starch 
and, in iron-haematoxylin-bismarck-brown preparations, presents a finely 
vacuolated appearance. 
Up to the present the sporogenous cells have been united together in 
one coherent mass, but now they show the first signs of separating from one 
another (Fig. 17). The separation takes place in ‘blocks’ quite com- 
parable with those described by Cardiff in Botrychium h In Helmintho- 
stachys, as in Botrychium , the separation appears to take place approximately 
‘ in the order in which the original walls were laid down in the archesporium 
and young sporogenous mass.’ The nuclei of the sporogenous cells of 
Helminthostachys are still in the resting condition when the separation of 
the ‘ blocks ’ commences. 
Delicate and undifferentiated as the walls of the sporogenous cells 
appear, they must nevertheless possess a greater complexity of structure 
than becomes apparent with our instruments, for during the process of the 
separation of the sporogenous cells from one another a middle lamella 
becomes mucilaginous and is finally dissolved, whilst a secondary thickening 
layer remains unaltered round each sporogenous cell. The entire sporo- 
genous membrane, both before and after the mucilaginous alteration of 
the middle lamella, gives no other reactions than those of pectic bodies. 
If I understand Stevens correctly, he found the mother-cells of Botrychium 
to be demarcated from one another and from the tapetum by a delicate 
plasmatic membrane alone, but Cardiff’s statements do not bear this out 
and it certainly does not apply to the mother-cells of Helminthostachys . 
The sporogenous cells now divide into the spore-tetrads. 
In the first division of the spore- mother-cells the chromosomes (which 
presumably occur in the reduced number) are seen to be small in size and 
rather crowded upon the spindle (Fig. 3). I have not succeeded in 
accurately counting their number, but I should very roughly estimate this 
to be between forty and sixty. Stevens has not recorded the number of 
chromosomes which occur in Botrychium. The spindle was surprisingly 
well preserved in the alcohol material and could be seen to terminate in 
very sharp, almost acuminate apices at which no traces of centrosomes were 
ever observed. The spindle extends to the very periphery of the mother- 
cell and is free from any radiations at its poles (Fig. 4). The daughter- 
nuclei, resulting from the first division, have in some of my preparations 
a curiously flattened, almost hemispherical shape when viewed in profile 2 
( Fi g- 5 )- They appear, like those of Botrychium , to enter into a resting 
1 Cardiff, 1. c., p. 342. 2 Compare this with Stevens’ Plate_XXIX, Fig. 28, 
