60 WRIGHT : THE GENUS DIOSPYROS 
is laid down in the epicotyledonary leaves long before they 
are exposed to light. 
As to the causes which lead to the detachment of the 
cotyledons, it is very difficult to make any definite state- 
men s. he regularity of the occurrence in seeds of all 
sizes, under natural and artificial conditions, is suggestive of 
‘heposs.b,htyof a definite cellular activity catting off the 
old lea 40 ”" n ° de ^ “ mMm9r Similar t0 tllat “ which 
cannot Te tte'le a!™” * ^ *"*' ™*’ h ° WeTer ' 
at -- 
i8 xr:^” th “ * he 
»nd sever* ££ "f" °‘ 8traiD ' 
this contention. The first is the ^ ’ “ Bnpport of 
In those speeies whel he cITT™ * ^ “ doBperm - 
endosperm may heeqoable<DPh yled< T ^ persistent the 
(D. sylvatica) ; 
speeies ^ith *" 
(D. insignis). Hence, thenr^ (D -l hirsuta ) or equable 
indicated by the absence o ^ ° f endos P erm . as 
substance, has probably verThttiT, ° f . rUmina ‘ ! ° n8 of this 
ment of the cotyledons. Abscond f° f° the rtetach ‘ 
obtained in the bulk of th» dfactoT 18 probably to be 
‘hough D^ovalifolia may pr„ Te end08penn ’ te8ta ’ &c - • tor 
those species with SZt ^ 6I “ pti »nal, it is . fact that 
a smaller quantity 0 f endosp^f^ haTe rela ‘ ivel ? 
exhausted early, resulting in a u • tleh 18 nece ®sarily 
liberation of the cotyled^s at ° f ** testa and 
However, neither of the foreon^ J d&te ' 
the increased resistance of the if copied with 
mature cotyledons, can comntot 1Fregnlar surface of the 
detachment «»«Pletely explain the cause of 
The chief cause in mw 
insufficient splitting of * *® *» found in the 
’ m t^ Proriens and D. 
