368 INTRODUCTION TO EMBRYOLOGY OF ANGIOSPERMS 



anatomical and cytological data, J0rgensen wisely refrains from 

 committing himself further but concludes that in any case the 

 present assignment of the Callitrichaceae to the Geraniales is open 

 to serious objection. 



Liliaceae-Allioideae. The extensive studies made on the family 

 Liliaceae by Schnarf, Stenar, and other embryologists have given 

 some new orientations to our ideas of the interrelationships between 

 the subfamilies and tribes included under it. Considering the sub- 

 family Allioideae, Krause (1930) lias divided it into four tribes, 

 viz., Agapantheae, Allieae, Gillesieae, and Miluleae. The embryol- 

 ogy of the last two tribes is relatively unknown and they will there- 

 fore be left out of consideration, but Stenar 's (1933) work on the 

 Agapantheae and Allieae indicates a much closer relationship be- 

 tween them than was previously anticipated. Indeed, as Stenar 

 says, Agapanthus and Tulbaghia are only South African Allieae 

 with a rhizome instead of a bulb, and in Tulbaghia the resemblance 

 extends even to the possession of the leek-like odor characteristic of 

 Allium. Regarding the relative positions of these two genera, 

 Agapanthus (ovule anatropous, parietal cells present, embryo sac 

 of Polygonum type) is to be regarded as the more primitive, and 

 Tulbaghia (ovule hemianatropous, parietal cells absent, embryo sac 

 of Allium type) as relatively advanced. The latter connects with 

 Nothoscordum which also has hemianatropous ovules devoid of 

 parietal tissue. Here the development of the embryo sac may be 

 of the Allium type (N. fragrans) or the Polygonum type (N. 

 striatum). 



Gagea, which was believed to have an embryo sac of the Adoxa 

 type (Stenar, 1927), used to be considered as the most advanced 

 member of the Allieae, but further work done on this genus revealed 

 that the embryo sac is of the Fritillaria type (see Maheshwari, 

 1946). The question arises, therefore, as to whether it should be 

 retained in the Allieae or transferred to the Lilioideae, where the 

 Fritillaria type is of general occurrence. In support of the second 

 alternative it may be added that even on other grounds Baillon 

 (1894) considered Gagea to be closely allied to Tulipa, which is a 

 member of the Lilioideae, and this assignment has been accepted by 

 Hutchinson (1934, 1948). 7 



7 See also Schnarf (1948). 



