Stevens. — Spore Formation in Botrychium virginianum . 471 
The massing of the plasmodial nuclei in the lakes of cytoplasm which 
occupy the larger clefts between the groups of mother-cells may have 
an important significance in the nutrition of the developing spores. Loeb 
(’ 99 ) came to the conclusion that enucleated cells lose their capacity for 
regeneration because the power of oxidation departs with the nucleus, and 
the synthesis which must depend upon the preliminary exercise of this 
power can no longer take place. From Lillie’s observations (’ 02 ) it seems 
clear that ‘ the oxidative activities of the organs must be largely a function 
of their extent of nuclear surface/ and ‘ the same conclusion applies also 
to synthetic processes in so far as they depend on oxidations/ In the 
light of these conclusions the massing of the nuclei of the plasmodium may 
not be merely an incident following the inflow of the cytoplasm. It may 
well be that there, where they occur associated in large numbers (see Fig. 47), 
they exert a powerful influence in the nutrition of the developing spores at 
the cost of the substance of the plasmodium itself. 
Methods. 
Small pieces of the sporophyll bearing only a few sporangia were fixed 
in the field as soon as they were cut off in the following manner : — The 
pieces of sporophyll were placed in a phial containing a 0-5 °/ o solution 
of chromic acid, from which the air was then removed by a portable air 
pump. When the atmospheric pressure was again turned on the infiltration 
of the pieces by the fixative was shown by their immediately sinking in it. 
The material was then transferred at once to Flemming’s fixative. Both the 
stronger and weaker solutions were employed, and both seemed to give 
equally good results. The material was embedded in paraffin, and thV 
sections, which were cut 5 microns thick, were stained by Flemming’s 
three-colour method. 
NOTE. 
After this paper was sent to the publishers a contribution by Ira D. 
Cardiff on ‘The Development of the Sporangium in Botrychium ’ appeared 
in tfie Botanical Gazette, xxxix, 5, p. 340. As the title indicates, Cardiff 
has made a study of the development of the sporangium rather than of the 
spores, and our papers cross the same ground chiefly as regards the tapetum. 
Cardiff worked with two species of Botrychium (B. virginianum and B. 
ternatum ), and he states that the two are found to be essentially the same 
in their sporangial development. The details of the paper and drawings do 
not refer to either species in particular, and I assume that they are intended 
to apply equally well to either. On this assumption it is interesting to note 
the differences that occur in members of the same species growing in dif- 
ferent localities (Cardiff’s B. virginianum was taken in the vicinity of 
Woodville, Ind.,and mine near Lawrence, Kans.). He finds that the tapetal 
