Stipules in the Stellatae , with special reference to Galium . 213 
five-membered whorls, stipules may be found which have been produced as 
the result of a coalescence of two primordia. Stipules of this kind ( = double 
stipules) possess either a forked midrib or two separate midribs, the apex of 
the stipules being at the same time more or less two-lobed. 
3. Double stipules may occur near the base, or towards the apex, and 
more rarely in the middle region of a stem. They may in certain cases 
represent a transition towards increase in number, in other cases a stage 
leading towards numerical decrease of the organs. Double stipules forming 
examples of both of these cases are occasionally found on one and the same 
stem. Sometimes, however, a decision on this subject is hardly possible. 
4. In the seedlings of several species examined of the genera Galium , 
Asperula , Crucianella , and Mericarpaea, the node or sometimes a few nodes 
succeeding the cotyledonary node as a rule bear a four-membered whorl, 
consisting of two true (opposite) leaves and two stipules alternating with the 
former. In the higher region of the stem the number of members in a whorl 
may in some of the species examined be gradually increased up to eight. 
5. The four-membered whorl is considered to represent the primitive 
type, at the same time indicating the probable character which prevailed 
among the direct ancestors of the Stellatae. 
6 . The six-membered whorl, which probably represents the type that 
characterized the ancestors of the Rubiaceae, is in the Stellatae regarded as 
having been derived from a four-membered whorl by complete fission 
(dedoublement) of the two stipules into four. 
7. Whorls with more than six members have no doubt originated by 
repeated fission of the original two stipules. 
8. Didymaea mexicana ) Hook, fil ., which bears two opposite leaves, and 
from two to often six, or rarely seven, scale-like stipules at each node, is 
presumed to approach the prototype of the Stellatae. And in this species 
also the four-membered whorl very probably represents the most primitive 
type. 
9. Galium paradoxum , Maxim., which bears two leaves and two scale- 
like stipules at the lower nodes and two true leaves and two leaf-like stipules 
in the higher region of the stem, is believed to be the most primitive species 
of the genus in this respect. 
The present investigation has been carried out in the Herbarium, Royal 
Botanic Gardens, Kew. All the specimens, except those of Galimm saxatile 
and G. Aparine y used for the investigation are preserved in the Herbarium. 
The writer has great pleasure in expressing his sincere thanks to Sir David 
Prain, C. M. G., C. I. E., for the privilege of working in the Herbarium and 
also using the Library. The writer also takes this opportunity of thanking 
Mr. L. A. Boodle for the constant encouragement, valuable help, and the 
interest he has taken during the progress of the investigation. 
Q 
