4 Stop es and Fujii, The nutritive relations of the surrounding tissues etc. 
food enters. Our work bas impressed on us tke remarkable 
uniformity in the structure of the thickened wall in all the Cycads, 
Ginkgo, and Pinus io which the big pits are closed hy a final 
lamella which can normally only allow soluble or semi-soluhle food 
to pass. 
All recent workers appear to unite in turning finally to the 
nuclei of the jacket cells as the factoryof protein nourishment for 
the egg cell, and do not carry the question further. Tkus ignoring 
the possible activities of the jacket cells themselves and their work 
as agents between the original supp ly of various food substances 
and the growing egg in which the food is required in a form 
available for immediate utilization. 
Materials and their treatment. 
V 
In the course of our investigations up> to the present we 
liave examined the following species: Cycas Beddomei , C. circinalis , 
C. Normanbyana, C . revoluta, and C. sp.P, Zamia floridana , Z. integri- 
folia, Z. muricata and Z. sp.P, Ceratozarnia fusco-viridis, C. mexicana , 
C. Miqueliana , Macrozarnia Preissii, M. spiralis, Encephalartos Hilde- 
brandtii, E. horndus, E. Lehmanni and E. sp.P, Dioon edule, Stangeria 
schizodon, Ginkgo, biloba, Pinus Cembra, P. montana , P. Pinea and 
P. sylvestris. 
In this first part of our work we have used for fixing 
Flemmings strong solution diluted with an equal volume of water; 
Alcohol acetic; Ckrom-acetic; and various strengths of Alcohol 
alone. In the case of the Cycads the best preservation of the 
structure of the egg cytoplasm without shrinkage was observed 
after using 90 °/ 0 alcohol, fixing the whole seed even when the 
stone layers had considerably hardened. For digestion experiments 
with pepsin also 90 °/ 0 alcohol proved to be the best fixative. 
With Flemming’s fixative we found that a very strong reducing 
substance present in the tissues caused excessive deposit of reduced 
osmium, and the resuits were not always satisfactory. With Pinus , 
particularly P. Cembra , where the endosperm is very large, we got 
excellent preservation of the structure of the egg cytoplasm by 
separating the endosperm from the integuments and uucellus, 
fixing in 30 °/ 0 Alcohol and then slowly transferring to higher 
percentages of alcohol. 
We also always examined fresli material whenever it was 
possible, for many of the substances which are important in the 
process of nutrition such as oxydases, sugars etc., cannot be dealt 
with in fixed material. 
For parafhn embedding we used Cedar oil chiefly (sometimes 
Chloroform) between the Absolute Alcohol and parafhn. Microtome 
series were stained with Flemmings triple stain, acetic methyl green 
(with or without the addition of Sodium sulphate) Congo red, 
ruthenium red, and other stains, or treated with aqueous solution 
of iodine, alcoholic solution of iodine in potassium iodide, Millon’s 
reagent, or Chlorzinc Iodine as the case demanded. Microtome 
