AN A A A DEN TEN 
| 
| 
I. INTRODUCTION 
The following study was begun during the summer of 1898 in 
the laboratory of the Botanical Institute in München upon the 
suggestion and under the direction of Professor K. Goebel. Only 
a small beginning was made in München on account of a very 
brief visit—a few weeks only—to that city. Since then the work 
has been carried on in New York City. 
In undertaking a comparative study of the embryology of the 
Rubiaceae it is expected to gain a knowledge of the life histories of 
a number of types sufficient to lead to a clearer understanding of 
the relationships between the genera of a very highly specialized 
and polymorphous family. It is intended at the same time to ex- 
tend the studies into the supposedly allied families, and thus to 
contribute, if possible, to the solution of the more general prob- 
lems of relationship among the higher dicotyledons. 
In addition to the problems of phylogeny there are those which 
arise out of the physiological relations existing between the 
sporophyte and the gametophyte. Modern morphology has 
acquainted us with the main facts in regard to the process of 
antithetic alternation of generation in the higher plants, and the 
general physiological relations which are the outgrowth of in- 
terdependence of sporophyte and gametophyte. Out of this inter- 
dependence, however, a large number of phenomena of both a 
structural and physiological character have arisen, offering a field 
of investigation hitherto neglected, to a great extent, but which 
latterly has been attracting not a little attention. The phenomena 
of adaptation in this connection are not a whit less interesting if 
more difficult to observe. In the present study these adaptive 
phenomena, so far as the writer has succeeded in observing them, 
will be set forth. It may, however, very properly be borne in mind 
that these phenomena are chiefly those of nutrition, and the small 
Memoirs, Torrey Botanical Club, Volume VIII. 
[No. 1, Part 1 (pp. 1-26), issued August 26, 1899.] 
