THE OVULE 



281 



and stigma, without stylar canal and ovular locule, and with almost no 

 histological differentiation throughout (Fig. 109). The gynoecia of 

 Balanophora and Langsdorffia are mere slender "emergences," with an 

 enlarged median section, in which is borne a single archesporial cell 

 (Fig. 109A). 



In all families of the Santalaceae, reduction of the ovule to arche- 

 sporial tissue is the ultimate stage. In the Balanophoraceae, this reduc- 



Fig. 109. Greatly reduced apogamous flower. A to G, Balanophora elongata: A, 

 longitudinal section of young pistillate flower consisting of a single simplified carpel 

 with a single embedded archesporial cell; B, cross section of an older flower; C, 

 longitudinal section of ovary with young archesporial cell; D, megasporogenesis, 

 second meiotic division; E, tetrad of megaspores; F, tetrad, with three spores de- 

 generating; G, mature spore. H, I, B. glohosa, 8-nucleate embryo sac and older 

 embryo sac showing disorganization of antipodals, egg, and synergids. (A to G, 

 after Fagerlind; H, I, after Lotsij. ) 



