440 BOTANICAL GAZETTE • [December 



cavity is filled in around the "foot," which remains in the seed as 

 an absorbing organ, so that the condition shown in fig. 26 results. 

 Sections of these embryos show that internally a root tip is 

 differentiated in a position shown by the triangle r in fig. 19. 

 A definite epidermis covers the cotyledons, hypocotyledonary stem, 

 and conical apex of the stem. After the procambium bundles 

 have differentiated, the foot or feeder is formed as a lateral pro- 

 tuberance of the hypocotyledonary stem, into which there is a 

 lateral extension of the tissues. The procambium bundles make a 

 deep loop toward the apex. In sections of an embryo at the stage 

 shown in fig. 21, conspicuous rows of cells, forming the laticiferous 

 ducts, are observed. In the region of the root tip these cells are 

 distinguished by their dense contents (fig. 27). Toward the apex 

 they are much longer (fig. 28), but have straight end walls in 

 which thickened portions were not observed. These correspond 

 to the younger ducts in G. Gnetnon figured by Bower. Young 

 sclerenchyma cells, with the characteristic paired nuclei, are also 

 present in these sections. 



Polyembryony 



It has been stated by Bower that polyembryony is the rule in 

 Gnetum Gnemon, as in other members of the group. From the 

 examples of it observed in G. sp. 15 and G. sp. 59 it is plain that 

 these species are not exceptions. Some of the variations of it are 

 represented by the diagrams in text-fig. 1 . In A three of the four 

 primary suspensors have developed extensive multicellular second- 

 ary suspensors measuring about 13 mm. These three have grown 

 so closely together that at this length one has not established itself 

 as the successful embryo, although the middle one is slightly in 

 the lead. In B are shown two competing embryos keeping pace 

 at a length of about 16 mm. The third, having separated from the 

 others, has become aborted at a length of 6 mm., while a secondary 

 suspensor has not developed from the other tube. In C only one 

 primary suspensor has developed a secondary one. This one has 

 already become quite massive in structure, indicating that it is 

 to become the mature embryo. A variation of this is shown in D. 

 Here two of the embryos have developed secondary suspensors, 

 but one is stunted, so that it is quite evident which is destined to 



