Notes. 
389 
tubercular disease, if it be a disease, is not infectious ; but it does 
clearly prove the influence of nitrate in the soil in diminishing the 
development of tubercles 1 . S. H. VINES, Oxford. 
ON THE DEVELOPMENT OP THE ENDOCAHP IN 
SAMBUCTJS NIGHA. — It is well known that those species of 
plants which produce succulent fruits are mainly indebted to animals 
for their means of dispersal, and it is necessary, in order that this 
end may be attained, that whilst the pulpy or fleshy portion of 
the fruit should be as attractive as possible, the seeds should be 
furnished with such characters as shall either prevent their being 
eaten at all, or shall enable them to pass through the ali- 
mentary canal with their powers of germination still unimpaired. 
This requirement is provided for, in by far the greater number of 
cases, by a hard envelope in which the seed or its essential parts are 
enclosed. These envelopes may be divided broadly into two classes, 
the one including those which are derived from a specially differ- 
entiated portion of the pericarp, and which is usually designated as 
the endocarp, the other comprising those coverings which, as in 
many true berries, form part of the seed itself. 
It is to the former of these two classes that Sambucus belongs, 
the development of which it is the object of this note to describe. 
If sections of the ovary of this plant be made while the bud is still 
very young, it is readily seen that the two innermost cell-layers 
which surround the 2-4 cavities containing the ovules are perfectly 
distinct both from each other and from those cells which lie im- 
mediately outside them, and that this difference is due to the peculiar 
mode in which cell-multiplication takes place in the two layers. 
In the innermost of these two layers, that which bounds the cavities 
of the ovary, the divisions occur regularly and exclusively in a plane 
at right angles to the long axis of the bud, that is, they are all trans- 
verse, whilst the few longitudinal divisions which mark the limits of 
the original cells do not increase in number at all. The impression 
which is gained of this layer taken as a whole, is that of a series 
of contiguous and hollow rings which bound the spaces destined 
eventually to contain the seeds. Each ring is of course divided 
internally into cells which correspond in number with the primary 
1 For a full discussion of this subject, and references to literature, see Ward, 
Some recent publications bearing on the question of the Sources of Nitrogen in 
Plants, in Annals of Botany, vol. i, 1887-8. 
