ANIMAL PRODUCTION, 671 



tions normal to the right testis. Attached to this organ was a normal epididy- 

 mis and vas deferens leading to the cloaca. Microscopical examination showed 

 that both sex glands were in a condition of extreme degeneration. Neither 

 spermatogenesis or ovigenesis could be found in any part of either gland. . . . 



" The case shows clearly enough that the secondary sexual characters of both 

 sexes may exist without the accomj)animent of functionating germinal epithe- 

 lium in the same individual. It does not i)rove that the secondary characters 

 may originally develop in the absence of the functioning of the primary glands, 

 because of the uncertainty as to whether either of the glands was ever functional 

 In this specimen. . . . The present case, of course, affords no direct evidence as 

 to whether a secretion influencing secondary sexual characters may not be pro- 

 duced by the interstitial or stromal cells. A further point of considerable inter- 

 est lies in the fact that in this bird we have a fully developed, noi'mal, and so 

 far as can be told, entirely functional oviduct in the absence of a functional 

 ovary." 



Barring' in Plymouth Rocks, W. J. Spillman {PouUry, 6 (1909), No. 1, 

 pp. 1, 8, l.'t, flffs. 6). — This is an explanation of how the transmission of barring 

 in Plymouth Rocks may be accounted for accoi-ding to the sex chromosome 

 theory. 



The peculiar inheritance of pink eyes among colored mice, W. E. Castle 

 and C. C. Little (Science, n. ser.. SO (1909), No. 766, pp. 313, Si^).— The authors 

 think that the dilute or pale series of color variations of mice and guinea pigs 

 is a qualitative and not a quantitative modification of the usual or intense 

 series. The dilution is demonstrably interchangeable from one color variety to 

 another, so that it may conveniently be treated as due to an independent factor. 

 The authors recognize 4 series of color varieties among mice, 2 dark-eyed and 2 

 pink-eyed. Specific illustrations are used to explain their views. Nine Men- 

 delian factors are now recognized as concerned in the color variations of mice, 

 namely, general color, dilution, spotting, pink-eye or paucity, yellow, brown, 

 black, restriction, and agouti. 



The mnemic sensibilities in their relation to the orig'inal sensations, R. 

 Semon (Die Miieiuisclien EiiipfindiiiKjcii in ihrcn Beziehungen zu den Orifjinal- 

 cmpfindiuigen. Leipzig and London, 1909, pp. XV-\-392; rev. in Nature [Lon- 

 don], 81 (1909), No. 2080, p. 302).— This is a further discussion and explana- 

 tion of the author's mnemic theory, by which he claims that the inheritance 

 of acquired characters can be proved. This theory may be considered a modified 

 form of Hering's memory theory. Permanent changes of living matter as 

 caused by external stimuli are termed " engrams," and the sum of engrams 

 in an organism is its " mneme." The inheritance of acquired characters is 

 accounted for by the transmission of the effects produced by the stimulus 

 from the organized matter first affected to all other parts of the organism, 

 either by nerve paths or by proplasmic intercellular filaments. In this way 

 faint engrams may be made on the reproductive organs. 



For further discussions of this theory see Darwin's presidential address 

 (E. S. B... 21, p. 318), and a previous note by Weisman and Semon (B. S. R., 

 IS, p. 1058). 



Telegony as induced reversion, O. F. Cook (Science, n. ser., 30 (1909), No. 

 IB'i, pp. 2'il-2.'i3). — A new point of view is suggested for looking at the facts 

 grouped under telegony. These facts are examples of reversion and are 

 sequels of hybridization. Hybridization, like other conditions, may influence 

 the expression though not the transmission of characters. Atavistic changes 

 appear more frequently in some series of hybrids than in others. " If rever- 

 sions prove to be more frequent after hybridization telegony will be estab- 



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