706 



SCIENCE 



[Vol. LV, No. 1435 



and arteries may not have the same fabrick as 

 those of the Intestines ... I propose to be con- 

 sidered and examined by persons of more acute 

 hands and judgment; as I do all what I have 

 here delivered, nor daring too much to trust even 

 the informations of my own hands and eyes, till 

 I find them confirmed by those of others, more 

 judicious as well as more dextrous in making ex- 

 periments. 



After two centuries Professor Carey lias sup- 

 plied the needed confirmation except in one 

 particular; he finds that the spiral winds in 

 the opposite direction! Carey describes a 

 "left-handed helix," — a spiral which reverses 

 the direction of the rotation of the embryonic 

 stomach and goes counter to the twisting of 

 the CBSophagus. But Dr. Cole recorded the 

 type familiar in dextral gastropod shells, which 

 accords with the rotation of the stomach. 

 Although it often happens in nature, as noted 

 by Thompson, that two opposite systems of 

 geodetic spirals exist together, and interfere 

 with one another, forming a criss-cross pat- 

 tern^ (and indeed such a, condition has been 

 recorded for the oesophageal muscles of rum- 

 inants-), it can not be invoked to reconcile the 

 conflicting statements regarding the direction 

 of the intestinal spiral, since both Cole and 

 Carey agree that there is but one well-defined 

 cleavage. Under these circumstances, the ques- 

 tion has been referred to Professor Sykes, who, 

 during the past season, while studying in the 

 Harvard Laboratory, has frequently unwound 

 the circular muscle of the intestine. Although 

 his results are to be published elsewhere, I am 

 permitted to report that he has verified the 

 early work of Dr. Cole in regard to the direc- 

 tion assumed by the spiral; it is dextral. If 

 this is so. Dr. Carey's explanation of that pri- 

 mary torsion of the embryonic intestine which 

 determines the disposition of small and large 

 bowels in the adult, though very ingenious, must 

 be considered illusory, for it depends on sinis- 

 tral coiling and tension.' 



The origin of the spiral trend of the muscles 

 is ascribed by Dr. Carey to "the rotating spiral 



1 Growth and Form, 1917, p. 489. 



2 Owen: Comp. Anat. of Vert., 1868, Vol. 3, 

 p. 470. 



3 Journ. Gen. Physiol., 1920, Vol. 3, p. 76 et seq. 



growth of the epithelial cells,"* but this 

 is a phase of the problem which invites further 



study. _, ^ ^ 



rREDERic T. Lewis 

 Harvard Medical School 



NEARCTIC FROTURANS 



The Protura — the most primitive of all the 

 insects, if indeed they are insects — were first 

 reported from the Nearetic Region in 1909. In 

 that year the eminent Italian zoologist and 

 entomologist, F. Silvestri, collected and de- 

 scribed under the name of Eosentomon wheeleri, 

 a single species from New York. For the 

 next twelve years no record was added from 

 the vast area of the Nearetic. 



The second record from this region was ob- 

 tained in 1921 from the vicinity of Washing- 

 ton, D. C, the fii-st specimen being found by 

 H. S. Barber, who accidentally came across it 

 in some leaf mold in which he was rearing 

 beetle larva. Other specimens of the same 

 species, which proved to be new, were soon 

 taken, and the species described by the writer 

 as Acerentulus barberi.''- 



Following the initial discovery at Wash- 

 ington the writer has been fortunate enough to 

 encounter Proturans in large numbers and in 

 considerable diversity at Takoma Park, Mary- 

 land. Here dui-ing the spring of 1921 no less 

 than twelve species, representing six genera, 

 were found, ten of them proving to be new. 

 These have been described in a paper presented 

 at a meeting of the Entomological Society of 

 Washington.- 



To these records obtained in the vicinity of 

 Washington are now added several more from 

 widely separated localities, and in some 

 instances from different life zones of the 

 Nearetic Region. These localities are as fol- 

 lows: Chesapeake Beach, Md. ; top of Blue 

 Ridge Mountains, near Bluemont, Va. (eleva- 

 tion 1,200 feet); near Prospect Hill, Va.; 



^Anat. Eec, 1920, Vol. 19, p. 220. 



1 " A Second Nearetic Species of Protura, 

 Acerentulus iarberi, new species." Ent. News, 

 Vol. XXXII, pp. 239-241. 



- ' ' New Genera and g^ecies of Protura, ' ' 

 Proc. Ent. Soc. Wash., Vol. XXIII, No. 9, pp. 

 193-202, PI. XVI. 



