July 13, 1900.] 



SCIENCE. 



71 



The work of Mr. Whipple is an invaluable 

 guide for the microscopical examination of po- 

 table water, in comprehensiveness and execution 

 far surpassing all previous manuals of the sub- 

 ject in the English language, or for that matter 

 in any other. It is also of great interest to the 

 biologist, since it summarizes from literature 

 not ordinarily gleaned the contributions of 

 many workers on various problems of fresh- 

 water ecology. It is to be hoped that this book 

 will serve as a stimulus to all engaged in this 

 field of applied biology to contribute to the so- 

 lution of the many unsolved problems which 

 their facilities and opportunities peculiarly fit 

 them to attack. Charles A. Kofoid. 



Illinois BioLoaicAL Station, 



University of Illinois. 



Analyse Chimique Qualitative. ParM.-E. Pbzzi- 



EscoT. Paris, Gauthier-Villars. 



This little book is instructive and valuable, as 

 the author, instead of following the beaten 

 track of qualitative separations, adopts mainly 

 the methods of M. Ad. Carnot, and of Engel 

 and Silva for metalloids. He gives especial at- 

 tention to the detection of the rarer elements, 

 utilizing methods of Cleve, of WyronbofF and 

 Verneuil, and others. 



Some of the methods of Carnot are rapid and 

 give elegant results ; the method of separating 

 cobalt, nickel, iron, zinc, manganese, thallium, 

 indium, and uranium, utilizing hydrogen per- 

 oxide may be particularly commended. 



Edwaed Kenouf. 



DISCUSSION AND COBBESPONDENCE. 



DEFOEMED STERNA IN THE DOMESTICATED 

 FOWL. 



The fact that the keel of the sternum is fre- 

 quently crooked in the domestic fowl has long 

 been known to me, but until the publication of 

 several papers either discussing the cause of 

 this deformation, or bringing it forward as an 

 instance of the inheritance of an acquired char- 

 acter, the reason for it had seemed quite evi- 

 dent. Now it may be that this is one of the 

 cases where a thing is not so simple as it ap- 

 pears to be on the surface, but the primary 

 cause for this curvature of the sternal keel 

 has always seemed to me enforced flightless- 



ness and consequent failure of the pectoral 

 muscles to pull the sternum straight, while this 

 may be aggravated by the feeding of corn 

 which forms flesh, but not bone. Another 

 factor would seem to be the effort to breed 

 fowls that shall be heavy in flesh, attempting 

 to increase the size of the pectoral muscles at 

 the very time the sternum is diminishing in size 

 from the disuse of these same muscles. Thus 

 while the sternum as a whole is degenerating a 

 larger keel is needed for the attachment of 

 muscles and under these conditions the only 

 way to obtain more surface is by the curva- 

 ture of the keel. It has been remarked that 

 thoroughbred fowls are more liable than others 

 to have deformed sternal keels and these it may 

 be noted are the very birds that get the least 

 amount of exercise. The games, and other 

 breeds not raised for flesh usually have straight 

 sterna while the heavy- bodied Asiatics are 

 particularly liable to have crooked sterna and 

 it may be said that the same deformation often 

 occurs among fancy pigeons bred for show and 

 deprived of exercise by being cooped up in 

 lofts. 



That a deformation inconstant in direction 

 and far from universal should not be regularly 

 inherited is not surprising; that it is due to 

 resting the breast on the perch, although this 

 may be one of various causes, is doubtful ; that 

 cases where the deformation seems to be passed 

 from mother to chick should be regarded as in- 

 stances of the inheritance of an acquired char- 

 acter is even more to be doubted. 



Finally it may be said that this twisting of 

 the sternal keel is much greater in a dried ster- 

 num than in one that is fresh or has been 

 soaked over night in water. Among the sterna 

 of Great Auk collected in 1887 not one was 

 straight, although they could be made straight 

 by soaking and it is a difficult matter to find a 

 straight keel on the dried sternum of a Murre 

 or Kazorbill. F. A. LucAs. 



REMARKS ON THE LOESS IN NORTH CHINA. 



Although there has been considerable discus- 

 sion regarding the loess of North China, there are 

 some facts which have not been presented with 

 sufficient prominence, although mentioned by 

 Pumpelly and others. In a trip of 450 miles 



