August 20, 1920] 



SCIENCE 



165 



nology cooperative plan offers to engineering 

 education. 



The officials of the company confess that 

 they expect to be the gainers by this policy. 

 Already there is an abundant evidence that 

 their hopes will be realized. The students 

 have been thrown together in a very intimate 

 relationship at the club house and have devel- 

 oped an intense loyalty to one another and to 

 the course which they are pursuing. 



There remains to be mentioned the effect 

 which this plan of study has upon the mental 

 condition of the student and upon his prog- 

 ress in acquiring theoretical knowledge. The 

 members of the instructing staff who have 

 come in contact with these students on their 

 return from Lynn are almost unanimous in 

 reporting that they show an increased mental 

 alertness, a greater fund of information con- 

 cerning all matters connected with their pro- 

 fession, and a wider interest in things in 

 general. That the General Electric Company 

 considers this educational experiment a suc- 

 cess is evidenced by the fact that they have 

 raised next year's limit of forty to sixty stu- 

 dents. The fact that the applications for 

 next year's class are five times as great as 

 they were last year is some indication of how 

 nearly the course has met the students' antici- 

 pations. 



Thus, although the plan has been in opera- 

 tion for one year only, it has already gained 

 the approval of the three parties most vitally 

 concerned : the students, the institute, and the 

 cooperating company. 



William H. Timbie 



Massachusetts Institute of Technology 



PARALLEL MUTATIONS IN THE 

 OSTRICH 



The account by Dr. A. H. Sturtevant of a 

 mutation (notch) in Drosophila funehrts sim- 

 ilar to one which has occurred several times in 

 D. melanogaster recalls the following sentence 

 in Darwin's " Origin," p. 179 : " As all the 

 species of the same genus are supposed, on my 



i"A Parallel Mutation in Drosophila fune- 

 hris," Science, July 19, 1918. 



theory, to have descended from a common 

 parent, it might be expected that they would 

 occasionally vary in an analogous manner." 



The problem of parallel mutations has lately 

 been impressed upon one by certain conditions 

 met with in the two-toed African ostrich, 

 Struthio. Four species of the genua have 

 been described, among which the most dis- 

 tinctive are the North African ostrich, 8. 

 camelus Linn., and the South African, 8. 

 australis Gurney. Owing to a recent importa- 

 tion by the Union Government of South 

 Africa of over a hundred specimens of the 

 northern bird which have been placed in 

 charge of the writer a unique opportunity has 

 presented itself of studying the northern and 

 southern ostrich side by side and also of ob- 

 serving the behavior of their characters in 

 cross-breds. 



Well-marked characters separate the two 

 species. The most important are: a differ- 

 ence in size, especially as regards the length 

 of the legs and neck; a different skin colora- 

 tion from the chick onwards, culminating in 

 a conspicuous contrast between the cocks at 

 the nuptial season; a bald patch on the head 

 of the northern bird, that of the southern be- 

 ing covered with short, hair-like feathers; and 

 differences in the size and shape of the egg, 

 accompanied by a pitted surface in the one 

 and an ivory smoothness in the other. The 

 characters represent germinal differences, 

 those of the imported birds being retained 

 under the new environmental conditions and 

 reappearing in all the progeny which have 

 been hatched. The birds cross freely and in 

 the first generation hybrids (F^) the bald 

 patch is found to be dominant, appearing in 

 all the hundred or more crosses reared, while 

 the dimensions and colors of the body and the 

 features of the egg appear as intermediates of 

 varying degree. Sufiieient time has not inter- 

 vened for the rearing of many second genera- 

 tion hybrids, (F„) only two having yet been 

 obtained. They however give every reason to 

 expect that segregation of the characters will 

 take place in the second generation. In what 

 ever manner this may occur there can be no 



