The Effects of Tropical Insolation, 
BY 
ALFRED J. EWART, D.Sc., Ph.D., 
Deputy Professor of Botany in Mason's College, Birmingham. 
I N a previous paper 1 an account has been given of the 
phenomena of assimilatory inhibition by insolation in 
the temperate regions, in which it was shown that most plants 
are resistant to ordinary exposure ; but that, in the leaves 
of certain Phanerogams and shade-loving plants, by prolonged 
exposure to perpendicular illumination, a generally temporary 
stoppage of C0 2 -assimilation, with or without an accompanying 
more or less complete decolourization of the chlorophyll- 
corpuscles, might be produced, whilst in certain Algae, Char a , 
&c., relatively short exposure might readily cause a stoppage 
of assimilation, generally accompanied, however, by a marked 
decolourization of the chlorophyll-corpuscles, and if at all 
prolonged being followed first by the death of the chlorophyll- 
grains of the part exposed, and finally by the death of the 
part . exposed in to to 2 . 
Advantage was taken of a stay in the tropics at Buitenzorg, 
Java, to corroborate and extend these observations; whilst, 
during a short stay in Ceylon, a number of accessory and 
1 Assimilatory Inhibition : Journal of the Linnean Society, 1896. 
2 Loc. cit. p. 439 ; and Journal L. S., Vol. XXXI, 1897, p. 573. 
[Annals of Botany, Vol. XI. No. XLIII. September, 1897.] 
