i80 THE JOUENAL OP INDIAN BOTANY. 



from certain of the Lobelideae in which the calyx may have been 

 entirely absent. Yet another instance is the formation of the reserve food 

 (endosperm) of the angiosperm seed out of apparently a second embryo 

 which has been spoilt by the fusion of its nucleus with the polar nucleus, in 

 order to replace the gametophyte, which, reduced in Gymnosperms, had dis- 

 appeared perhaps with the necessity for limiting the size of the ovules in the 

 closed carpel. The peculiar secondary thickening of the larger Monocotyle- 

 dons and the polystely of Ganera may be explained on the same lines i.e. 

 that the original mode of thickenning has been lost, and when in the course of 

 evolution the necessity for a thicker stem again arose, had to be replaced by 

 a different method. On this hypothesis too she suggests, that the floral 

 envelope of Naia is not a reduced perianth, still less a rudimentary one, but 

 a new structure evolved to take the place of a lost perianth. The new Law 

 is thus in accord with the view that the primitive angiosperm flower was 

 of the type now in the Ranales, and is not to be found among the Archiohla- 

 mydeae, as assumed in the ' continental ' systems of Eichler and Engler, and 

 affords pleasing support for the older system of the Qenera Plantar 

 rum of Bentham and Hooker, in so far at least that in it the Ranunciilaccic 

 were placed first, and the apelalae last of the Dicotyledons with the Monoco- 

 tyledons after. Mrs. Arber supports her hypothesis with instances drawn 

 from the evolution of animals, in which the Law of Loss had previously been 

 enunciated in another form. The essay is most interesting and suggestive, 

 and well worth attention. It is in conformity with the idea of the absolute- 

 ness of inheritance, towards which so much modern work seems to point. 



P. F. F. 



Histology 



McLean, R. C. Sex and Soma. 



This was the title of a communication read at a meeting of the Liuhaean 

 Society on November 20th, 1919, with reference to the occurrence of multinu- 

 cleate cells in higher plants, as described especially by Dr. Arber and Dr. Beer, 

 in a paper which was abstracted in the November issue of this journal, p. 94. 

 The papers has not appeared in print, and the following is taken from the 

 published minutes of the meeting. 



" The Author enlarged upon the recently discovered phase of multinuc- 

 leosis in the developing soma cell of higher plants .... and maintained, in 

 opposition to Arber and Beer, that there is evidence of nuclear reunions taking 

 place in the multinuclear cells. He characterized these fusions as modified 

 sexual conjugations consequent upon the long series of vegetable divisions in 

 the lineage of a soma cell, and necessary to avoid the degeneration which 

 experiment shows to be attendant upon prolonged vegetative propagation. 

 The development of the plant body may thus be regarded as embracing two 

 phases of stimulus : firstly, the normal sex stimulus which initiates the period 

 of maximum cell proliferation, and, secondly, this somatic nuclear union, 

 initiating the period of maximum differentiation. Tissue differentiation, it 

 was suggested, may be associated with some process of segregation subse- 

 quent to this nuclear fusion ... It was finally suggested that germinal 

 modifications as well as somatic segregations may be derived from a mecha- 

 nism of nuclear fractiontzation and subsequent partial reunion in somatic 



cells." 



P. F. F. 



