the Protein Bodies of Zea ) Ricinus , and Conopholis. 353 
ripening of the seed. ‘ Dass Wasserentziehung die Hiillmasse veranlasst, 
zeigen evident noch nicht vollig gereifte Samen, welche man nach Entfernung 
der Schale einige Stunden an der Luft austrocknen lasst. Denn nun findet 
man eine Hiillmasse welche in dem Samen zuvor nicht vorhanden war, 
gebildet.’ Pfeffer seems to have had the idea that the protein granules 
were crystalline in shape from the start, as he states that (l.c., p. 458) 
Nageli’s explanation, namely, that globular protein granules gradually took 
the form of crystals, did not hold for Ricinus . 
Sixteen years after the appearance of Pfeffer’s paper, Wakker (1888) 
published his results of an extended study upon the contents of plant-cells. 
His account of the formation of protein granules in Ricinus is briefly as 
follows: The formation of endosperm (1888, p. 453) proceeds from the 
periphery towards the centre. In a nearly mature seed all stages in the 
development of endosperm cells are to be found. The youngest cells, 
which lie in the centre of the young seed, have a wall-layer of cytoplasm 
with a distinct nucleus and a large central vacuole. The cytoplasm is 
unevenly finely granular. The cells are in active? division, and inclusions 
are lacking. Farther towards the periphery the cells are smaller ; the 
nucleus lies in the centre of the cell and is in connexion with the parietal 
cytoplasm by numerous fine strands. The granules are numerous and 
larger, covering the nucleus, and thereby obscuring its sharp outline. 
Proceeding towards the periphery the plasmic strands of the cells become 
more numerous, dividing the original vacuole into more or less spherical 
vacuoles which impart an almost frothy appearance to the cytoplasm. It 
is in these spherical vacuoles that small bodies appear, lying exactly in the 
centre and frequently showing molecular motion. In older cells these 
bodies are larger, and their true nature is seen. They show sharp corners 
and edges, and we may assume that they are the youngest stages of 
the crystalloids. The application of reagents demonstrates this with 
a certainty. 
Wakker makes no mention of the presence of starch in the young cells, 
as pointed out by Pfeffer and by Maschke 1 (1859) and Gris 1 (1864). 
Werminski (1888) claims that aleurone granules arise as a precipitation 
from albumin in solution in vacuoles during the ripening of the seed. 
According to the findings of Rendle (1888, p. 162) the aleurone grains 
of Lupinus digitatus first appear as small bodies lying in the cytoplasm. 
They stain more deeply than the protoplasm itself with iodine, haematoxylin, 
Hoffmann’s blue and eosine, and the staining is perfectly homogeneous. He 
shows that there is no crystalline or globoid contents in the protein granule, 
i. e. no solid mineral content, a claim made apparently by Pfeffer. As to 
the origin of aleurone grains, Liidtke (1890) agrees with Pfeffer. 
De Vries, basing his conclusion upon the investigations of Wakker, 
1 Mentioned by Pfeffer. I have not had access to the original papers of these authors. 
