154 THE CHEMISTRY OF THE PLANT 
Formaldehyde—Con. 
Asparagin 
C4HsN203, (CO(NH2) — CH: 
— CH(NH:) — COOH). 
Chitin 
CisHsoN2012 
Vanillin 
CsHs03 
Hadromal (composition uncer- 
tain) 
hydrates. Found free in 
minute quantities in leaves 
when active photosynthesis is 
occurring. 
This is found, especially in the 
growing regions, in many 
plants, e.g. asparagus, peas, 
beans, vetches, beet roots, 
potatoes, etc. 
This forms part of, or in some 
cases is the chief constituent of, 
the cell wall of many of the 
lower plants, eg. Myxo- 
phyceae, Mucorales, Carpo- 
myceteae. It was long con- 
sidered a form of cellulose 
(“fungus cellulose’). It 
forms the body wall of insects, 
crustaceans, etc. 
Formed by the fermentation 
of the seed pods (‘‘beans’’) of 
the Vanilla plant, whence it is 
extracted by alcohol. It is 
present in most if not all 
lignified cell walls and is 
possibly one of the substances 
giving the cell wall the char- 
acters that we call ‘lignifica- 
tion’’ (see hadromal), 
This is a substance separated 
by Czapek from lignified cell 
walls and believed by him to 
be what gives them their 
“‘lignified”’ character. On the 
other hand many botanists do 
not consider this as the impor- 
tant body and ascribe lignifica- 
tion to the presence in the cell 
walls of coniferin and vanillin 
(q.v.) and perhaps other sub- 
stances. 
