BOOKS AND CURRENT LITERATURE ISM 



vegetative shoot, the wall of the ovary being a stem in its morphological 

 origin. The author believes that the ovary of this cactus was superior 

 in its primitive condition, and that its present inferior position is due to 

 gradual submergence of the stem-like fertile shoot by the active growth 

 of the surrounding parts. The seeds retain their viability for many 

 years but will not germinate without the puncturing of their heavy 

 coats. Since this is the only known case in which seeds persist for 

 years in a fruit which remains moist, an ingenious experiment was 

 devised in which filed seeds were again placed in fruits, with moisture 

 and temperature conditions favorable for germination, but no activity 

 resulted. Sterile seeds are frequent but are not outwardly distinguish- 

 able from fertile ones. Seedlings are unknown in nature, the perpetua- 

 tion of the plant depending chiefly on the dissemination of the readily 

 detached and easily rooted vegetative joints. The fruits which fall to 

 the ground no longer possess the ability to give rise to flowers, but take 

 root, under favorable conditions, and produce vegetative shoots. The 

 author states that there is no evidence to indicate that Opuntia fulgida 

 is on the road toward a loss of the power of seed production and a 

 total dependence on vegetative multiplication, but it is difficult to 

 follow his reasoning in this particular. 



The publication is amply illustrated both with respect to the gross 

 features of the fruits and the anatomical development of the fruit, 

 flower, and accessory parts, and the work as a whole constitutes a very 

 thorough investigation of one of the most striking cases of aberrant 

 floral behavior among our native plants.- — Forrest Shreve. 



THE PLANT WORLD, VOL. 22, NO. 6, 1919 



