162 BOTANICAL GAZETTE [august 



Embryo. — -The proembryo consists of a filament of three cells, 

 of which the terminal forms the embryo, while the other two form 

 a long suspensor of two tiers of two cells each. The cells of the 



4 8 



pensor have very little cytoplasm and are m 



Endosperm. — The endosperm nucleus and 

 same time. The endosnerm nuclei divide 



taneously. The endosperm is parietally placed and does not mass 



proembr\ 



development 



52, 53). Some sterile ovules were found, but the tendency 

 toward sterility is not so pronounced as in the clovers. 



Discussion 



- 



Guignard's account of Trifolium (3, pp. 119, 120) is limited 

 to the development of the embryo. The fertilized egg produces 

 a filament of 3 cells, the terminal of which develops the embryo. 

 The other 2 cells produce a short, several-celled suspensor. In the 

 later stages the line of separation between embryo and suspensor 

 is indistinct. The dermatogen is differentiated in the octant 

 stage. In the three species of Trifolium investigated by the writer, 

 the suspensor is more massive and the dermatogen is differentiated 

 later than the octant stage. 



In Medicago arbor ea Guignard (3, pp. 119, 120, figs. IQ2-1Q4) 

 reports a one-celled archesporium and two superimposed parietal 

 cells. The megaspore mother cell functions directly to produce the 

 embryo sac. The proembryo produces a long, filamentous suspen- 

 sor which is distinct from the terminal embryo. The dermatogen 

 is differentiated in the octant stage. In Medicago saliva there is 

 usually a multicellular archesporium, production of megaspores, and 

 more parietal tissue, but in other features it is similar to Medicago 

 arborea. In Vicia sepium, Guignard (3, p. 53, figs. 66-70) found 

 one parietal cell which occasionally makes one transverse division. 

 The single megaspore mother cell produces a longitudinal row of 3 

 cells, the lower 2 being megaspores, or a longitudinal row of 4 

 megaspores; in each case the lowest megaspore functions. The 

 proembryo produces a long suspensor which consists of two rows 

 of cells and is distinct from the embryo. In Vicia americana a 



