768 



SCIENCE 



[N. 8. Vol. XLII. No. 1091 



of the subject from the point of view of physio- 

 logical plant anatomy. That point of view is 

 for the present, however, somewhat under a 

 cloud in this country because it does not ap- 

 peal to the morphologist and the evolutionist 

 on the one hand or to the cultivator of the dis- 

 embodied plant physiology at present in vogue 

 in these United States, on the other. When 

 the physiologist among us again begins to 

 recognize the importance of plant structures, 

 he will possibly find a work conceived in this 

 manner useful. 



E. 0. Jeffrey 



America's Greatest Prohlem: the Negro. By 

 R. W. Shufeldt, M.D., major, medical corps. 

 United States Army, member Association of 

 American Anatomists, fellow of the Ameri- 

 can Ornithologists' Union, etc. Philadel- 

 phia, 1915. Eoy. 8vo, pp. 3YY, with fifty- 

 two illustrations. 



Unfortunately this volume has been heralded 

 as " a wonderfully startling book . . . certain 

 to instantly arouse a vigorous nation-wide 

 discussion," and — ^by implication — as " an 

 authoritative . . . guide to the solution of this 

 menace of the deterioration of the Caucasian 

 race in America." Nevertheless (these hyper- 

 boles being credited to the mercantile enthu- 

 siasm of the publishers, whose part has been 

 done quickly and well), a notice of it was 

 undertaken by the present writer partly be- 

 cause of his interest in the Negro, and partly 

 because he took for granted that the author, a 

 well-known ornithologist and comparative 

 anatomist, would materially increase our 

 knowledge of the facts involved, facilitate our 

 comprehension of the nature and causes of the 

 existing undesirable relations between the races, 

 and offer something novel as " a remedy 

 whereby the peril may be safely passed." 



These expectatons have not been met. On 

 the contrary, while the author's earnestness is 

 evident, a careful and unprejudiced examina- 

 tion of the volume leads the reviewer to wish 

 that the time and energy expended upon it had 

 been devoted to the strictly scientific work 

 which the author had in hand (p. vii) ; that 

 might, at least, have been free from the need- 



lessly frequent references to topics connected 

 with psychopathia sexualis which characterize 

 this and some of his other publications. 



Burt G. Wilder 



SPECIAL ARTICLES 



ZYGOSPORES AND RHIZOPUS FOR CLASS USE 



Ehizopus nigricans — the common bread 

 mold — is the form most frequently used in the 

 microscopic study of fungi in elementary 

 classes in botany. Its production of both 

 sexual and non-sexual spores, added to the 

 ease with which it may be obtained and grown 

 without refined laboratory facilities, makes it 

 an ideal form for class study. The zygo- 

 spores, though not difficult to find, have been 

 overlooked by most teachers and many re- 

 quests have been made of the writer for infor- 

 mation in regard to methods of obtaining 

 them. It has seemed desirable therefore to 

 publish a short note on the subject. 



Bhizopus is commonly found in nature on 

 decaying fruits and vegetables as weU as upon 

 bread which has been kept in a moist atmos- 

 phere. The air is so full of its spores that 

 almost any substratum rich in carbohydrates, 

 if kept under proper moisture conditions, will 

 produce a spontaneous growth of the fimgus. 

 The essential precaution is to insure a moist 

 atmosphere and at the same time to prevent 

 the substratum itself from becoming so moist 

 as to stimulate the growth of bacteria. A 

 simple method is to line a tumbler with moist- 

 ened filter paper or even newspaper and to 

 place a piece of bread on some non-absorptive 

 object inside that will keep it from contact 

 with the moist paper on the sides and bottom. 

 The bread should be moist but not wet — the 

 consistency of fresh bread is ideal — and the 

 container should be kept closed. A bell jar 

 lined with moist filter paper covering a dish 

 with water or moist paper on the bottom, also 

 makes a good moist chamber. Within a week, 

 if the air has been kept moist, a good growth 

 of the mold will result. Green molds will 

 often be present as well, but the Ehizopus is 

 so rapid in growth that contamination with 

 other forms will not generally be seriously 

 troublesome. Zygospores will sometimes be 



