r 92o] HAINING—GNETUM 





437 



<• 







off from the apex of the suspensor. Then 



m 



No mention is made of long secondary suspensors, such as those 

 observed in G. sp. 15 and G. sp. 59; but the description of the 

 differentiation of the tissues in the embryonic body is in accord 

 with that given later for these species. Reference is also made 

 to seeds of an unknown species in which the suspensors form a 

 coiled bundle in a cavity in the endosperm. This corresponds to 

 the condition found in the ripe fruit of G. sp. 29; but it is stated 

 that in the individual suspensors a single large nucleus appears 

 toward the tip of the tube, and no reference is made to the peculiar 

 cell which is present in G. sp. 29. 



Lotsy examined G. Gnemon in 1899. He described the exten- 

 sive suspensor-like elongation of the fertilized egg, the branching 

 of this tube, and the cutting off of an embryo cell at the tip. 



Coulter (3) reinvestigated the early stages in the development 

 of the same species in 1908. He found that in the formation of 

 the suspensor free nuclear division takes place, resulting in a few 

 nuclei scattered along the suspensor, which are often separated by 

 transverse walls. He describes a terminal embryo cell containing 

 one of the free nuclei which continues to divide, accompanied by 

 cleavage walls until a multicellular embryo is formed. This account 

 differs from that given by Bower in this respect, that the earlier 

 writer described an apical cell as functioning, and no free nuclear 

 division. ' 



In 191 6 Thompson (6) published observations on the embryo 

 of several species of Gnetum. Differing from Lotsy's account, he 

 states that the fertilized egg of G. Gnemon divides into two cells, 

 both of which develop into suspensors without transverse cleavage 

 walls. In G. sp. 33 he describes a proembryo consisting of a small 

 group of irregularly arranged cells, produced by division of the 

 fertilized egg. Each of these cells then elongates, forming a tor- 

 tuous suspensor which contains normally only one nucleus, although 

 the possibility of the occurrence of several nuclei would not be 

 excluded in all cases. Finally, he observed the suspensors of 

 G. moluccense growing outside of the endosperm, between it and 

 the nucellus. He states that the tips of the tubes enlarge within the 



