440 
Notes . 
There is no difficulty in explaining the whole anomaly. It is a well- 
known fact that in several species of Aroideae the leaf-blade presents 
a certain number of oval or oval-oblong holes, which are the conse- 
quence of unequal growth, during prefoliation, in the tissues close to 
the primary nerves and those between them. Such holes, however, do 
not occur in Anthurium crassinervium ; but in the case here described 
there must have been at least a first step towards their formation, that 
is to say, a slight break or rupture in the internerval tissue, just 
sufficient to neutralize the small amount of lateral traction. The leaf 
having an involute ptyxis, its under surface has of course a higher 
degree of tension than the upper one, and thus the two severed 
borders of the break would bulge out a little, but not enough to 
destroy the inner contact of the adjoining epidermis. The surface of 
the leaf at this period is moreover of a certain viscosity, which no 
doubt contributed to maintain adhesion and facilitated fresh coalescence 
on the ventral surface, whilst the free borders on both sides of the 
rupture-line continued to grow outwards and by little and little became 
the laminar enations mentioned before. 
2. Some years ago a friend of mine gave me a leaf of the mango- 
tree (Mangifera indica , L.), which had on its under surface a secondary 
leaf growing from the midrib, and recently another mango-leaf was 
shown to me, where the accessory leaf belonged to the upper surface. 
Both secondary leaves are in the shape of little boats, adhering with 
their keel to the midrib of the primary leaf. Their own median 
nerve is evidently a piece of the outermost fibro-vascular bundles of 
the original costa, so that there is no free extremity. Like in similar 
instances recorded in works on teratology, the convex side of the 
accessory leaf is of the same appearance and structure as the adjoining 
surface of the large leaf. 
Dr. Maxwell T. Masters mentions the case of an orange-leaf which 
appears to belong to the type here described ; he abstains, however, 
from giving an explanation and says only what it cannot be \ 
I beg leave to proffer the following interpretation, which I believe 
is quite new, although based on facts well known to all those who 
have given some attention to the teachings of modern vegetable 
physiology. 
1 Veget. Teratology, 1869, p. 446. I have not seen the German translation of 
the work, which is said to contain many corrections and additions by the author ; 
I therefore do not know whether the passage quoted above has been altered or not. 
