398 
introductions? The somewhat haphazard 
but none the less important and skillful 
work of Albert Koebele, first for the United 
States government, afterwards for the State 
of California, and now for the Hawaiian 
government, is certainly an indication, 
taken in connection with what we have 
shown, that thorough experimental work 
with predaceous and parasitic insects 
promises, in especial cases, results of possibly 
very great value. 
We wish no more destructive birds like 
the English Sparrow ; we have no desire to 
make an American resident of the Indian 
Mongoos, nor have we any desire to import 
the Australian flying fox as a pet. Neither 
do we desire to allow any more European 
plants to escape from cultivation and 
emulate the Russian Thistle. But there are 
many absolutely beneficial insects of Pale- 
arctic regions which might flourish amongst 
us, and whose intentional introduction could 
not be harmful from any point of view, while 
they might be of the greatest service. 
L. O. Howarp. 
WASHINGTON, D. C. 
PHYLOGENY AND TAXONOMY OF THE AN- 
GIOSPERMS.* 
Ir is unnecessary for me to state at the 
outset, what is evident to every botanist, 
that it is as yet impossible to present a 
complete phylogeny of the angiosperms. 
Phytopaleontology is too young a science, 
and the materials with which it deals are as 
yet far too scanty to have given us direct 
evidence as to the phylogeny of all families 
of plants. No one can trace with great 
certainty from the fossil remains of plants 
yet discovered the genealogy of any con- 
siderable portion of the vegetable kingdom. 
It will be many a year before the direct 
evidence we so much desire will leave no 
*An abstract of the address of the retiring president, 
delivered before the Botanical Society of America, 
Toronto meeting, August 17, 1897. 
SCIENCE. 
[N.S. Vou. VI. No. 141. 
considerable gaps to be filled by skillful in- 
terpolation. However, after making all 
due allowance for the imperfection of the 
record, there are many facts as to past 
vegetation which are well established. 
Thus we know that the earliest plants 
were simple, homogeneous-celled, aquatic 
organisms. We know that ferns and gym- 
nosperms preceded angiosperms. We know 
that the angiosperms which first appeared 
were of lower types, and that the highest 
types known to-day were wanting until 
very late in geological time. 
It is true, moreover, that we are not 
confined to the direct evidence furnished 
by the paleontological record. In the indi- 
vidual development of every plant (its 
ontogenesis) there is a recapitulation of its 
ancestral development (phylogenesis). A. 
eritical study of the development of the 
individual must throw light upon the past 
history of the species. When we know 
every step in the formation of each plant 
we shall be able to trace the phylogeny of 
every species. Here, again, we have to face 
the fact that our knowledge is still quite 
fragmentary and that on this account the 
results are not as definite as we could wish, 
and yet, when we bring together what we 
know of the ontogeny of plants here and 
there in the higher groups, we are able to 
make out with much certainty not a little 
as to their phylogeny. To the details re- 
garding these results I will advert some- 
what later. 
There is still another line of inquiry open 
to us, namely, the morphological, in which 
account is taken of the varying deyelop- 
ment of homologous tissues, members and 
organs. Rightly interpreted, the results of 
morphological studies are of very high im- 
portance in determining genetic relation- 
ships. When differences in homologous 
parts are regarded as but the expression of 
variation from a common form they be- 
ome indices of relationship, and when 
