322 Descendenz und Hybriden. — Morphologie und Teratologie. 



Kapteyn, J. C, Skevv frequency ciirves in biology and 

 statistics. (Publ. Astron. Lab, Groningen, and P. Noord- 

 hoff. Groningen 1903. 45 pp.) 



This littie book contains the results of an independent in- 

 vestigation of the subject, because the author found that 

 Pearson's theory of skew curves was open to grave ob- 

 jections. In the first 10 articles the generation of skew curves 

 is explained in a populär way for non-mathematical readers. 

 The matheinatical treatment of the problem is given in articles 

 11 — 15. In articles 16 — 22, are given extensive precepts and 

 illustrations of the different processes by numerical examples, 

 so that the practica! investigator of biological problems, who 

 is unable to follow the argument of the mathematical articles, 

 will find nevertheless the application of Kapteyn 's theory a 

 comparatively easy task. The Director of the Botanical Garden 

 at Groningen (Netherlands) will send a copy to any Bo- 

 tanist who expresses his wish to receive it. Moll. 



Peacock, E. A. Woodruffe, The Lincolnshire Oxlip. 

 (Naturalist. No. 582. july 1905. p. 203—205.) 



After summarising the different hybrids and sub-hybrids 

 between P. acaiilis L. and P. offlcinalis L. viz. the two simple 

 hybrids, either hybrid crossed with either parent and var. 

 caiilescens Koch of P. acaiilis, the author proceeds to consider 

 these so-called oxiips. It is an interesting fact that in fairly open 

 woods or bushy banks the hybrid is 9 acaiilis X cf officinalis, 

 whilst in open meadows aud poor pastures it is rf acaiilis X 

 9 officinalis. Only the sub-hybrid {acaiilis X officinalis) X 

 acaiilis has been found in the field and is confined to open 

 woods, where the primrose grows together with the hybrid. 

 The author regards the var. caiilescens as being P. acaiilis 

 crossed again with the just-mentioned sub-hybrid; it only grows 

 where the latter occurs together with the parent forms. It is 

 suggested that primrose, cowslip and oxlip can hardly yet 

 be called „species", since they are very much given to crossing 

 and recrossing and every wild Lincolnshire intermediate 

 form met with by the author has been of hybrid origin. 



F. E. Fritsch. 



BiLLiNGS, F. H., A study of Tillandsia iisneoides. (Botanical 

 Gazette. XXXVIII. August 1904. p. 99—121.) 



The development and fertilization of the embryosac in this 

 species presents no peculiar features. The development of the 

 embryo is slow and no considerable size is reached until the 

 autumn of the samc season. The germination of the seeds, 

 which are kept from falling to the ground by the adherent hairs 

 of the testa, was observed in the wet spring of 1903. The 

 chloroplastids are peculiar in this species being compounded 

 according to the author's description out of a number of smaller 



