332 BOTANICAL GAZETTE. | Dec., 
per cent. of the 81 species collected on that island. Lastly, 31, or 
38 per cent. of the whole flora of Clemente is reported also from 
Guadalupe ; and 35, or only 23 per cent., of that of Catalina is 
common to itself and Guadalupe. More significance attaches to 
this latter analysis than to the others, as it seems to indicate a 
closer relationship between the floras of Clemente and the distant 
Guadalupe than obtains on the two nearer islands.’ 
t this point it is proper to refer back to the statement made 
in relation to the antiquity of Clemente, that the geology and 
present flora of that island were not in apparent harmony. This 
hypothesis, determined by the scantiness of peculiar species, is far 
from conclusive. Greater antiquity would afford opportunity for 
the extension landward of many perhaps original species whose 
local identification would thus be absorbed and lost forever ; and 
if the faintest value be attached to the common methods of seed 
dispersal, facilities have occurred for the distribution of a score of 
distinctive floras; and while strongly disparaging those very 
methods in general, their specific force and application is readily 
conceded where the barrier to isolation becomes contemptible, in 
view of the stupendous lapses of time since the seas first swept 
the uppermost terraces of Clemente. 
rom all the foregoing we briefly suggest : 
Ist. Present variation and constant modifications in matter of 
size point to the mutability of species upon these islands. 
2d. The large percentage (16) of the whole flora being char- 
acteristic, tends strongly to indicate insular genesis. 
3d. That there are no barriers which some species can not 
overcome ; while the close restriction of others to local habitats 
and seeming to enjoy greater facilities for expansion than the first 
named, would indicate that the latter species were too short-lived 
to acquire the adaptability and availability for extension possesse 
by the former. 
4th. That the material available for investigation is of too 
conflicting a nature to formulate even a scientific “ guess” as to 
primative origin of the floras of these islands. 
he discovery of a new genus on Catalina and Santa Cruz®, 
whose definite characters and relationship is not yet wholly set- 
tled, but whose nearest apparent affiliation is native of northern 
Mexico, might lead us to inquire for some such derivation; but 
Mr. Watson has shown how unlikely is this to be the case with 
°Since making the above analysis, the i ies and extension 
: > publication of some new species and ex 5 
y erehanaiys of ergo by ae “ties 3 = his recent revised supplement to the igen F a mag 
‘ ects xactitude of the enu i | to vi 
general conclusions. merations given, but not enoug 
_ ©Proc. Am. Acad., vo!. 20. : 
