204 
Takeda. — Some Points in the Morphology of the 
may be presumed that each of the three stipules arises from an inde- 
pendent primordium. The middle stipule, as a rule, shows no definite 
connexion with either of the adjacent stipules. The writer has, however, 
found a case in which one of the two stipules on one side of a node 
is divided about halTway into two unequal parts (Fig. 16), 1 thus suggest- 
ing how three stipules may have arisen from two by fission of one of 
them, that is, if two be taken as representing the fundamental number 
of stipules on each side of the node. 
A feature of further interest has also been found in several speci- 
mens examined of Didymaea , the paired stipules on either side of the 
stem being not uncommonly united into a single organ, with the lamina 
either deeply or shallowly divided (Figs. 17, 18). There is, of course, 
Figs. 14. 15. 16. 17. 18. 
Figs. 14-18. Interfoliar stipules of Didymaea mexicana, Hook. fil. All x 5. (Figs. 15 and 
16 were taken from inflorescence, the others from stem.) Explanation in the text. 
no shadow of doubt that these single stipules with a forked lamina are 
produced as the result of a concrescence of two separate primordia. The 
question then arises whether the presence of a single stipule on either 
side of the stem should be considered as the more primitive type, and 
if this were so, whether the occurrence of two to three separate stipules 
on each side of the node might be regarded as the result of a fission 
of the original single interfoliar stipules. 
A comparison of the different features found in Galium and other 
genera with those just described above for Didymaea will bring forward 
the more general question : whether the six-membered whorl in the 
Stellatae should be regarded as having been derived from a four- 
membered whorl, owing to chorisis of an original pair of opposite interfoliar 
stipules, or whether, on the other hand, the production of only two stipules 
at a node is due to reduction. 
An examination of the seedlings may throw some light on the problem, 
since early stages in ontogeny often show some ancestral characters. 2 
1 Unfortunately, the material was unsuitable for determining whether the two midribs of this 
stipule are completely separate or united near the base of the organ in question. 
2 It is not maintained that characters observed in early stages of ontogeny are necessarily to be 
