io6i 
Sporangia and Spores of Aneimia phyllitidis . 
Pfeffer ( 97 ), however, contrary to de Vries, sets forth that within the 
cells a sufficiently rapid distribution of materials could take place with the 
assistance of mechanical bendings, and variation in cell-turgor, tissue tensions 
and temperature. While all these things must be operative, in the light of 
Bierberg’s results there seems great probability that the plasmodium habit 
of the tapetal cells may be for the distribution of food by cytoplasmic 
movements, as well as for setting free the nuclei that they may assemble 
immediately about the gonotokonts and their descendants (Figs. 5, 6 , and 7). 
Fig. 7 shows that such movement has actually occurred, for here the 
cytoplasm has to a large extent forsaken the periphery of the sporangium 
and accumulated about the gonotokonts. On comparing PI. LXXXIV, 
Figs. 6 and 7, and PI. LXXXV, Figs. 11 and 13, we have evidence that the 
cytoplasm migrations begin when the tapetum first breaks down and continue 
through the subsequent stages of sporangial and spore development up to 
the maturity of the spores. It seems, therefore, highly probable that in this 
particular instance a distribution of nutrient materials within the sporangium 
may be aided by a more or less constant plasmodial circulation. 
It will be noted, on comparing PI. LXXXIV, Fig. 2, and PI. LXXXV, 
Figs. 8 and 9, that the sporangia and sporogenous cells increase in size up to 
the time of synapsis in the nuclei of the gonotokonts ; then growth is lessened 
while the meiotic divisions are taking place. After this it appears from the 
increased size of the vacuoles in which the young spores lie (Pig. 11) that 
the sporangia resume their growth for a time, while the young spores remain 
in size about as they were when first formed. In this stage no vestige 
appears of a wall of the gonotokonts, and the young spores lie widely 
separated in the vacuole that formerly held their respective gonotokonts. 
After a time, however, the plasmodium creeps in between the spores and 
holds each one separately embedded (Figs. 11 and 13). Miss Twiss (’ 10 ) 
finds a similar early disappearance of the gonotokont wall in Lygodium , but 
in Aneimia hirsuta she still finds traces of it after the walls of the spores 
appear in the tetrad. 
The separation of the gonotokonts from each other is initiated by their 
assuming a spherical form (compare PL LXXXIV, Figs. 4 and 7). Thereupon 
it appears that the tapetal plasmodium creeps in between them and shoves 
them more or less widely apart, while at the same time the nuclei of the 
plasmodium become dispersed among and around them, as shown by 
PL LXXXIV, Fig. 7, and PL LXXXV, Figs. 9 and 10. That the gonotokonts 
are in a condition of growth at this time is seen on comparing Pl. LXXXIV, 
Fig. 4, and PL LXXXV, Fig. 9, and that it is also a critical nutritive period 
is attested by the fact that one finds not infrequently whole sporangia now 
beginning to disintegrate. 
When the last division is complete, as shown in PI. LXXXV, Fig. 10, the 
plasma membrane of a gonotokont persists as the common outer membrane 
