THE CASUARINZ. 117 
Species. Average, 
160 calcareous ‘ i ; ‘ ‘ p08 
6457 non-calcareous : : 5 2°65 
Parasites.—The parasitic plants sintelaetl in the British lists were 
so few in number, that but little dependence could be placed on the 
averages obtained from them. In the Continental flora we have a 
British species, a low degree of dispersion. Species which are sup- 
posed to be semi-parasitic, but are probably never restricted in their 
choice of victim-plants (Rhinanthee and , give, on the con- 
ite a ae average; and this agrees with thee former "result. The 
gures 
. Average, 
58 + conalets parasites . : : : - “223 
62 semi-parasites > : ° ° - 38°50 
6487 non-parasitic : ° : ° . 2°59 
SPERSION IN RELATION To BABIT.—Zrees and shrubs.— 
British ree were found to Mag a. more widely than her- 
baceous plants over land, rathe ver sea.” This remark 
— with equal force to Continental ac of which only 3 (or 3 
ent. of o Pp. 
almost half of which (41 per cent.) cross the Atlantic, the smaller range 
of trees over sea reduced their degree of dispersion below that of herbs ; 
in the case of the Continental jon of which only a small fraction n of 
} : g 
raises 
above that of herbs. The following averages show that Continental 
shrubs aby a lower degree of dispersion than herbs, as was the case 
with British :— 
a Average. 
89 “ieee : ; Q . é 3 OS i 
hrubs . é Fi : 5 : < 236 
SURE habe : ; wo 
Creeping rhizomes or aoe _The mean ‘dicen of ‘repent’ 
plants, as compared with others, corresponds with that eaten 
from 6 lists :-— 
POST repent oe ee ee ae 
6386 non-repent : ° . : 
(Zo be continued.) 
Tue CasvaRine. 
Recherches sur les Casuarina, et en particulier sur coux de ss 
Nouvelle-Caledonie. Par M. Jutes Porsson. (‘‘ Nouvelles Archives du 
Muséum, ” yol. x., 1876. — _— the cotyledons are oo 
and are provided with stomata scattered over the surfaces, while th 
pes ora adnate leaf-scales (phyllichnia) a thei stomata aang 
