The Incapacity of the Date Endosperm for 
Self-Digestion. 
BY 
RAYMOND H. POND, 
North-Western University, Chicago. 
Introduction. 
T HAT the digestion of nourishment stored in the endosperm is accom- 
plished by the influence of enzymes which are secreted, or at least 
become active under conditions of germination, is universally accepted. 
The results and conclusions of various investigators are by no means 
uniform, as to whether or not the enzymes are developed in the embryo 
only or also in the endosperm independently of the embryo. The prevailing 
opinion, as recognized by Pfeffer, is that the endosperms of many grasses, 
palms, &c., possess a capacity for auto-digestion ; that is, that such endo- 
sperms from which the embryos have been removed will, under optimum 
conditions of germination, provided digestion products may easily escape, 
digest themselves and become depleted of their storage substance. This 
view has become so widely accepted as no longer to be questioned. 
When one examines the evidence upon which this conclusion rests he 
is surprised at its weakness. Moreover, associated with this view is a con- 
ception which is wholly out of date. The various authors have regarded 
as an almost self-evident fact that digestion by enzymes is evidence of 
vitality. The idea that a given tissue which happens to contain something 
capable of doing enzyme work is to be regarded as living matter, is no 
longer modern. 
This paper is intended to show, first : that the literature as it stands 
does not furnish convincing proof of auto-digestion by endosperms, and 
second, that the date endosperm which Puriewitsch found to be capable of 
auto-depletion, and which he regards as living matter, does not possess 
such capacity. 
The weakness of the evidence as presented by various authors is in 
nearly every case to be explained by unreliable data. For instance, the 
seeds have been allowed to germinate before removing the embryo when 
[Annals of Botany, Vol. XX. No. LXXVII. January, 1906.] 
