496 



SCIENCE 



[N. S. Vol. XXXIII. No. 



orbit, temporal and nasal regions, and the 

 visceral arch derivatives are considered sepa- 

 rately. The author publishes, for the first 

 time, two new views of the skull of a twenty- 

 millimeter embryo which combine numerous 

 interesting relations. It is a pity that the 

 details of these figures are not better shown 

 in the half-tones. Anatomical illustrations 

 are being steadily improved, and this is shown 

 in many figures in this edition; but far more 

 care is yet required in both the printing and 

 selection of suitable paper, before the stand- 

 ard of German editions can be approached. 

 The chapter closes with an extended account 

 of the ossification of the individual bones of 

 the skull. 



The development of the muscular system is 

 described by W. H. Lewis in about seventy 

 pages. We find this an excellent account, well 

 planned and comprehensive, while at the same 

 time concise and logical. The influence of a 

 participation on the part of the writer in 

 embryological studies of an experimental na- 

 ture is quite evident and gives a modem point 

 of view. 



The chapter is well illustrated, many of 

 the figures being original, and some published 

 here first. It is possible to obtain from them 

 and the text a good idea of the origin and de- 

 velopment of the various muscle groups. 

 The author's contributions to the development 

 of the muscles of trunk and limbs, and more 

 recently of the head, tongue and larynx, are 

 outlined here with figures from his new 

 models. Futamura's striking series of pic- 

 tures representing the stages of spreading of 

 the facial musculature forms an interesting 

 feature. 



Only twenty-four pages are allotted to the 

 last section, including the septum transversum 

 diaphragm, and the coslom, but the subject is 

 brought up to-date by Mall with the aid of 

 new investigations in addition to his previous 

 extensive studies and the conditions found 

 in a number of recently described young hu- 

 man ova. Broman's work is also incorporated 

 to advantage. 



One praiseworthy feature is the extensive 

 bibliography at the end of each chapter. 



Though the printing of the illustrations 

 and the general make-up of the German edi- 

 tion is decidedly superior to the English, the 

 American publishers have, on the whole, suc- 

 ceeded in making the volume a creditable one. 

 The second volume, now in press, will be an- 

 ticipated with much interest. 



H. McE. Knower 

 Cincinnati, Ohio, 

 February 18, 1911 



SPECIAL ARTICLES 



■^THE ORIGIN OF NINE WING MUTATIONS IN 

 DROSOPHILA* 



In the following preliminary report I wish 

 to put on record some of the principal wing 

 mutations that have appeared in cultures of 

 the fruit fly, DrosopMla ampelophila. In 

 another communication I shall describe five 

 mutations in eye color that have been found 

 in the same cultures, and their modes of in- 

 heritance. The theoretical questions involved 

 must be deferred until the complete data can be 

 published. These mutations have appeared in 

 such rapid succession that my time has been 

 almost entirely consumed in producing pure 

 strains of the new forms, which can be util- 

 ized later for a thorough study of the inherit- 

 ance of the new types. I wish here merely to 

 call attention to the fact that while most of 

 the new types breed true from the start, others 

 do not ; and also to the fact that while certain 

 of the mutations are sex-limited other muta- 

 tions involving the same organs do not show 

 this form of inheritance. It may appear that 

 we have here an opportunity to learn some- 

 thing further of these different modes of in- 

 heritance appearing in the same animal. One 

 fact especially will impress itself on any one 

 who follows the history of these new types, 

 viz., the " segregation " of the characters, and 

 in most cases the absence of intergrades. 



Beaded Wings. — In May, 1910, a number of 

 flies, pupse, larvse and eggs of DrosopMla were 

 subjected to radium rays. One fly was pro- 



^ The main facts in this paper were given before 

 the American Society of Zoologists, December 29, 

 1910. 



