306 PROF. F. O. BOWER ON APOSPORY AND ALLIED PHENOMENA. 
together with the enlargement of the stalk (s/.), are still better seen in specimens which 
have been germinated for some time on damp soil (Plate LVII. fig. 7). Неге the arche- 
spore may be seen in process of disorganization, while the superficial cells of the head and 
those of the stalk have increased greatly in size beyond the normal. Тһе elongation of 
such specimens may be very considerable (figs. 8, 9), the whole being a solid massive body, 
sometimes of irregular outline (fig. 5), and showing, as regards the form and arrangement 
of its cells, nothing of a characteristically prothalloid character ; but in the thin cellulose 
walls, plentiful protoplasm and chlorophyll, as well asin the occasignal presence of glan- 
dular hairs (fig. 10), they resemble typical prothalli. Outgrowths of the sporangia such 
as these, of an irregularly cylindrical form, and while still attached to the parent frond, 
may produce antheridia of the normal type (fig. 11). This has been repeatedly observed 
no such outgrowths while still attached to the decaying pinnule from which they sprung, 
and the position of the antheridia has been seen, as shown in fig. 11, to be but a few cells 
removed from tissues which are characteristically those of the sporophore. This massive, 
irregularly cylindrical type of development was found to be very prevalent in cultures 
made during the present year (1886), at normal temperatures, but with protection from 
frost; whereas in cultures made in 1884, in a hothouse at Kew, it was found that the ' 
type of development was, as a rule, a more near approach to that of the normal flattened 
prothallus, and that in those specimens a characteristic apical growth frequently appeared, 
which was entirely absent from such specimens as those in figs. 10, 11, «с. Thus in 
fig. 12 is shown an example of an irregular, flattened, lateral growth from the enlarged 
stalk of a sporangium, the archespore of which is still plainly to be seen. In fig. 13 is 
shown a further example of an irregular flattened body derived from a sporangium, in 
which growth with a characteristic apical cell has begun laterally. Further, in fig. 14 
(Plate LVIII.) is shown a fair type of thé development of a flattened prothallus, as it 
might be seen in the eultures of 1884, the irregular outgrowth from the sporangium 
having finally settled down into a flattened form of growth, with wedge-shaped initial 
cells at more than one point. The result is a flattened prothalloid body approaching to 
the normaltype. As these high-temperature cultures progressed, the approach to the 
normal form became more and more close; subsequently sexual organs were produced 
(fig. 15), and finally from them were derived numerous young sporophores. Thus the 
cultures carried on at Kew have led to the same result as those already recorded by Mr. 
Druery as having previously been carried on by himself*. Further, on young plants 
raised from the “ pseudo-bulbils " by Mr. Druery the phenomena of sporal arrest can be 
already seen, accompanied by substitutionary vegetative growth ; thus, so far as experience 
goes at, present, the peculiarities of the variety are handed on to the second generation. 
The question remains as to the nature of those bodies which Mr. Druery found in 1883 
on this Fern, and described and figured in this Society's Journal + under the name of 
“ pseudo-bulbils." They have not recurred in their full development either in his cultures 
of subsequent years, nor yet in those at Kew. As the result of observation of numerous 
* Journ. Linn. Soc., Bot. xxi. pp. 358-360. 
t L.c. p. 855; also p. 358, fig. 1. 
