NOTE 
ON CELL-REGENERATION IN BOTRYTIS CINEREA.— The formation 
of cell-membranes as a response to traumatic stimuli has been very completely investi¬ 
gated in many groups of plants, 1 but with the exception of certain Mucorineae 2 little 
is known of this process in the Fungi. During the course of an investigation of 
Botrytis cinerea it was necessary to examine minutely fragments of mature growths 
teased out in water. Many of these preparations were maintained for several days, 
and regenerative changes in the injured mycelium were frequently noted. In these 
observations, which were merely incidental to the main work, no attempt was made to 
do more than record the behaviour of the living fungus, occasionally aid being sought 
in the use of intra-vitam stains such as neutral red, methyl violet, and especially 
Congo red. 
The healing process and the rapidity with which it occurs depend to a large 
extent upon the age and condition of the particular cells affected. Speaking generally, 
hyphae which have been starved show less regenerative power than mycelium growing 
upon a physiologically suitable pabulum. No obvious effect of temperature or light 
was noted, although a more thorough examination devoted to this particular purpose 
might reveal its presence. Different regions of the same mycelium react unequally 
to approximately the same type of injury, the regenerative response apparently being 
related largely to the condition of vacuolation of the protoplast. Young actively- 
growing vegetative cells are usually filled with non-vacuolate homogeneous protoplasm, 
whilst of the older cells, those retaining cell-content usually exhibit a multi-vacuolate, 
honeycomb-like appearance. The conidiophores are highly specialized organs of 
strictly limited growth. The basal region is tinted and consists of mechanically rigid 
thick-walled cells in which the protoplast is disposed as a thin parietal layer about one 
or infrequently two large vacuoles. The upper sporogenous region is hyaline and 
thin-walled, and the cells are densely filled with homogeneous, finely granular or 
minutely vacuolate protoplasm in an extremely active condition. The latter cells 
possess by far the greatest capacity for regeneration : the vegetative hyphae and 
particularly the older vacuolate cells show this potentiality to a markedly less degree; 
whilst the cells of the lower region of the conidiophore are almost devoid of it. 
In general the types of injury which have been observed to stimulate a healing 
reaction may be grouped into three categories ; (i) acute flexion of cells; (2) punctures 
and relatively minute wounds ; (3) relatively large superficial lesions. In certain 
injuries two distinct regenerative processes are involved: restitution of the original 
1 See Kiister, E.: Pathologische Pflanzenanatomie, Jena, 1903, where the important literature 
is cited. 
2 Cf, especially Van Tieghem, P.: Ann. Sc. Nat. Bot., 1875. 
[Annals of Botany, Vol. XXXII. No. CXXVIII. October, 1918.] 
