40 GENETICS [BoT. Absts., Vol. VII, 



are also included in the greater cells. Eggs which have taken their origin from the larger 

 megaspores are capable of fertilization, as proved by the chromosome sets in hybrids between 

 plants of the section Caninae and normally sexual roses. In spite of the sexual potency of 

 the Caninae their propagation is almost exclusively apomictical. This fact explains the con- 

 stancy of the mentioned chromosome sets. Type 10 must be supposed to be originated by 

 fertilization. — "All species and forms investigated, belonging to the section Caninae — i.e., 

 the majority of the examined roses, originated in Europe, North Africa and West Asia — are 

 very ancient hybrids representing the Fi generation, which, ever since its origin thousands of 

 years ago, has been maintained owing to apomictical reproduction." The anorthoploids rep- 

 resent Fa or any later generation of crosses. The apomictical reproduction was probably 

 induced by these ancient crosses. To explain all the chromosome sets in the Caninae, the 

 existence of octoploid and decaploid sexual forms is assumed. The enormous polymorphy in 

 the Caninae is to be ascribed to hybridism. Also vegetative mutations produced in apomic- 

 tical stocks have no doubt contributed to the polymorphy. — K. V. Ossian Dahlgren. 



244. Thomson, Godfrey H. On the degree of perfection of hierarchical order among 

 correlation coefficients. Biometrika 12: 355-366. 2 fig. Nov., 1919. — Derivation of Hart- 

 Spearman criterion for degree of hierarchical order (degree in which correlations of anj' two 

 mental tests with others are in same sequence of magnitude) neglects important term. With 

 correlated dice throws, where true correlations are known a priori, criterion exaggerates 

 perfection of hierarchy. — John Rice Miner. 



245. Vandel, M. a. Sur la reproduction des Planaires at sur la signification de la 

 fecondation chez ces animaux. [On the reproduction of some Planarians and on the signifi- 

 cance of fecundation in these animals.] Compt. E,end. Acad. Sci. 171: 125-128. July, 1920. 



246. Weatherw.\x, Paul. A misconception as to the structure of the ear of maize. 

 Bull. Torrey Bot. Club 47: 359-362. 6 fig. Aug., 1920.— An attempt to refute the evidence 

 published bj' Collins which indicated that the ear of maize may have developed through the 

 twisting of yoked pairs of spikelets. The author contends from an examination of the 

 cobs of several mature ears that dropping of rows of seeds is due to the discontinuance of 

 a row of paired spikelets and not to the loss of the pedicelled spikelets from yoked pairs, as 

 suggested by Collins. In conclusion it is stated that there is no in(Mcation that short rows 

 represent long rows partially aborted, but that the abortion of spikelets or of rows in the ear 

 seems to be much more constant as a characteristic of theories than of real ears. Figures 

 four and six apparently have been transposed. — J. H. Kemplon. 



247. W[eston, T. a.] [Rev. of: [Diener, Richard]. The law of hybridizing discovered 

 by Richard Diener. SO .r 27 cm., 15 p., 8 fig. Richard Diener: Kentfield, California, [1920.] ] 

 Florists' Exch. 50: 554. Sept. 11, 1920.— See also Bot. Absts. 7, Entries 181, 231, 248. 



248. W[eston, T. A]. The law of hybridizing. Florists' Exch. 50: 981. Nov. 6, 1920.— 

 Reply to William H. Phipps's criticism of the author's review of [Diener, R.] The law of 

 hybridizing discovered by Richard Diener. See Bot. Absts. 7, Entries 181, 231, 247. — G. H. 

 Shull. 



249. WoLL, F. W., AND Paul L. Dougherty. Advanced registry testing of dairy cows. 

 California Agric. Exp. Sta. Circ. 218. 15 p. 1920. — Presents arguments for the advanced- 

 registry testing of pure-bred cows, cites records made in California, and gives instructions 

 on how to initiate such a test in California. — John W. Gowen. 



