254 GENETICS [BoT. Absts., Vol. X, 



flowers in the "Golden Flame" variety of P. zonale are treated in detail. The inclusion of 

 cells belonging to one form within tissues of the other is especially noted. — A variegated 

 form of Spirea Ulmaria devoid of functional germ cells resembles the totally sterile "Freak 

 of Nature" zonal Pelargonium described earlier. This shows that, although varieties pro- 

 ducing new forms from root cuttings may be regarded as periclinal chimeras, other possibilities 

 must be remembered. Many herbaceous variegated plants arranged periclinally may give 

 shoots composed entirely of either internal or external constituents. These are not always 

 endogenous, but may be originated by a periclinal division in the cortical layers. Attempts 

 to breed root cuttings with parent plants have been unsuccessful. — E. B. Babcock. 



1679. Berry, Reginald Arthur, and Daniel Grant O'Brien. Errors in feeding 

 experiments with cross-bred pigs. Jour. Agric. Sci. 11: 275-286. 2 fig. 1921. — In experi- 

 ments in feeding two lots of pigs, one of 43, and another of 46, each for 16 weeks, conditions 

 were so nearly comparable that combining results of the 2 trials was permissible for statistical 

 purposes, as proved by mathematical test. The probable error in rate of gain for 1 pig, in 

 terms of average daily gain, was 7 per cent; for pure-bred pigs of the same litter and of similar 

 live weight, 3 per cent; and for cross-bred pigs of similar weight but of different parents, 

 4 per cent. The error, greatest for a short feeding period, decreases rapidly week by week 

 up to 7 weeks, after which the rate of decrease is slow. The errors on IS separate pens of 

 4 pigs each varied from 2.3 to 12.0S per cent, averaging 6.21 per cent. An increased daily 

 rate of gain decreases the probable error; the converse is also true. The rate of gain in female 

 pigs was depressed slightly by a period of heat, but the difference between gilts and barrows 

 was only 0.02 pounds. The stage of fattening did not affect the error, although well-fattened 

 animals showed a greater range in rate of gain than those only partially fattened. — Edioard 

 N . Wentworth. 



1680. Blakeslee, Albert F. Mutations in mucors. Jour. Heredity 11: 278-284. S fig. 

 1920. — In the examination of about 38,000 progeny of single asexual spores from cultures of 

 the hermaphrodite mould, Mucor- genevensis, many variant forms were seen. In the subse- 

 quent asexual generations of most of these forms the normal strain appeared and gradually 

 predominated to the exclusion of the variant. However, 2 of these mutants have been shown 

 to be stable, at least for many generations. The "Dwarf" mutant lacks asexual spores and 

 also zygospores, and has been grown unchanged for nearly 7 years. Mutant "A" lacks her- 

 maphrodite zygospores, has a strong minus sexual reaction, and only a feeble plus one. This 

 form has been grown for 16 generations and appears stable. Among the inconstant mutants, 

 "X," a hermaphrodite with a plus tendency, had low white growth and large zygospores; 

 in the course of years its cultures reverted to the normal type. Mutant "D," which had a 

 yellowish dense growth and was almost without zygospores, had a minus tendency, and seems 

 to have finally reverted. The "Yeast" mutant was composed of separate cells in its early 

 stage of growth. In the course of time only normal forms were found among the progeny. — 

 Johri Belling. 



1681. Blaringhem, L. A propos de I'heredite des fascies de Capsella Viguieri. [Con- 

 cerning the heredity of fasciations in Capsella Viguieri.] Compt. Rend. Acad. Sci. Paris 169: 

 298-300. 1919. — This unique plant, named and described by the author in 1910, is claimed to 

 be the best known example of the sudden birth of a new species. For 12 generations the 

 tendency to produce fasciated stems has been maintained as a constant character. The 

 only other true-breeding fasciated species known is cock's-comb, Celosia cristata L. In 

 both species the fasciated character is amplified by cultural conditions favoring vegetative 

 development, i.e., by transplanting to rich soil under glass. De Vries has pointed out an 

 apparent relation between fasciation and tricotyledony in Amaranthus retroflexus, but in 

 Capsella Viguieri the author observed but 4 tricotj'ls among 3000 seedlings examined. — 

 Merle C. Coulter. 



1682. Bliss, A. J. Unusual forms of Iris flowers. Gard. Chron. 70: 149. 1921.— Of 

 abnormal flower forms the tetramerous occurs most frequently among the author's seedlings 



