136 Proceedings of the Royal Physical Society. 
within a cell; thus the amount of available food-material 
may diminish, or the ease with which food is absorbed 
may be interfered with. 
Thus a cell containing two attractive spheres, and a nucleus 
with four nuclear chromatin segments, would have greater 
difficulty in obtaining and absorbing food than a cell with 
only one sphere and a nucleus with two segments, because of 
the well-known principle first applied to Biology by Leuckart 
and Spencer, that the surface of a growing spherical cell - 
increases as the square, while the contents increase as the 
cube of the radius. | 
We have thus far seen that “cell organs” such as chloro- 
phyll-bands, attractive spheres with their central corpuscles, 
and chromatin segments, are transmitted from parent to 
offspring, but that also the general cell-plasm and the 
nuclear achromatins, nucleoli and endonucleoli, are trans- 
mitted I have fully proved for the conjugating cells within 
the Embryo-sac of Angiosperms, cells which give rise to the. 
primary endosperm nucleus. The stages in the formation of 
the latter in Myoswrus minimus may be summed up thus :— 
1. Amceboid movements of the cell-plasmata of the two 
primordial (7.e., naked) cells, leading to conjugation of 
the cell-plasmata. 
Approximation of nuclei and formation of paranucleoli or 
accessory nucleoli, which probably undergo degene- 
ration. 
3. Flattening of nuclei on contact, and absorption of inter- 
vening nuclear membrane. 
4. Conjugation of nuclei (union of the various contents of 
both nuclei). 
5. Approximation of nucleoli (due to contractile action of 
threads within the nucleus ?). 
6. Conjugation of nucleoli (and in all probability of the 
endonucleoli). Casting off of (male ?) nucleolar bag. 
bo 
What is of special interest in this fecundation is not the 
mere transmission of nucleoli, but the fact that we should 
meet with not only a reduction in the number of chromatin 
segments, but also with a diminution in the amount of 
