December 28, 1883.] 



SCIENCE. 



835 



a stimulus to the vaso-motor and cardio-inhibitory 

 centres of tbe medulla; but, in opposition to the siate- 

 meuts of Traube and Landois, he asserts that it dis- 

 ables the intrinsic motor centres of the heart. He 

 grounds this statement on the fact, that, after section 

 of the vagi and the cervical cord, the heart soon ceases 

 to beat, when the .animal breathes in an atmosphere 

 containing from twenty to forty per cent of carbon 

 dioxide. Breathing in an atmosphere of oxygen 

 stimulates both the inhibitory and accelerator centres 

 of the medulla: and the author repeats for the mam- 

 mal a statement made with reference to the frog; viz., 

 that oxygen acts as a constant stimulus for the heart- 

 contractions. Want of oxygen, like carbon dioxide, 

 stimulates the inhibitory and vaso-motor centres, and 

 first stimulates, then depresses, the .accelerator centres. 

 — {Arch. anat. pl)yxiol.,lSS3,VU.) w. H. ii. [582 



Maturation and impregnation of the mam- 

 malian ovum. — G. Rein h,as investigated these phe- 

 nomena in rabbits and guinea-pigs, lie describes 

 minutely his manner of obtaining the desired mate- 

 rial. In rabbits the tuba can be cut open, and exam- 

 ined with a lens: in guinea-pigs it is better to collect 

 the eggs by pressing out the excised tuba with a blunt 

 instrument. They may be examined fre^h in the 

 fluid from the oviduct, and even kept so for some 

 time, if the cover-glass is surrounded by a rim of oil, 

 and the slide placed in a warm box. To preserve the 

 eggs, fix with (.1%-!%) osmic acid, place them for 

 two or three days in Miiller's fluid, and mount in 

 glycerine. 



The so-called corona radiata consists of the cells 

 (changed to the spindle form) of the discus piolige- 

 rus. It is most marked in the rabbit immediately 

 before the bursting of the Graafian follicle, i.e., nine 

 to eleven hours after copulation ; by wliich time one 

 polar globule has generally been formed. The cells 

 of the corona present features most unusual in epi- 

 thelia: they are elongated, spindle or star shaped, 

 with processes which branch often and anastomose 

 with one another; they are probal)ly forced apart by 

 the liquor folliculi, which accumulates, especially 

 during the last hours before the bursting of the fol- 

 licle; after that event they resume their original 

 form. As the ovum matures, the nucleus is distended, 

 and assumes an eccentric position and oval form. 

 The nucleolus is replaced now by a cluster of grau- 

 ule3,wliich then scatter themselves through the yolk, 

 become smaller and ultimately indistinguishable. 

 The nucleus comes to lie close against the zona pel- 

 lucida, and there is flattened out. The next change 

 is the expulsion of the first polar globule, which ap- 

 pears to be formed out of the germ-vesicle. No kary- 

 okinetic figures were observed in connection with 

 the process. Hein suggests that possibly the mam- 

 malian polar globules are not complete homologues 

 of those of the lower animals. The maturation is 

 further marked by the contraction of the yolk, first, 

 at the point where the polar globule is ejected; sec- 

 ond, general, so that the yolk recedes, as in other 

 mammalia, from the zona pelliicida. In three cases 

 active protuberances on the yolk were observed (cf. 

 Eupiler, ante, i. 1132). In the mature ovum also 



appear yolk-grains larger and much darker than the 

 other griinules. In four cases a second nucleus was 

 observed more in the centre of the egg, probably the 

 egg-nucleus (or female pronucleus). 



Impregnation takes place in the middle third of 

 the tuba thirteen to seventeen hours after copulation. 

 Two pronuclei (male and female) are seen in the 

 ovum: they travel towards one .another, meet eccen- 

 trically, make amoeboid movements, and sometimes 

 are quite near the surface. The radiating lines could 

 not be seen in most cases around the pronuclei. At 

 the time of impregnation the cells of the corona 

 have partly fallen oft'. Numerous spermatozoa crowd 

 around the egg, several pass the zona ; but probably 

 only one enters the yolk. The pronuclei pass to the 

 centre of the ovum, the amoeboid movements con- 

 tinue; one pronucleus becomes crescent-shaped, and 

 embraces the other: the two then probably unite. — 

 (Arch, mikros. aitat.. xxii. T-',.i.) c. s. M. [583 



Duration of systole and diastole of heart- 

 beat. — From a series of exporiinents made upon the 

 dog, Howell and Ely have come to the conclusion 

 that variations of arterial pressure from fifty milli- 

 metres to a hundred and sixty millimetres of mercury 

 have no direct effect whatever upon the duration of 

 either systole or diastole. The experiments were 

 carried out upon hearts completely isolated from 

 every other oig.in of the body, except the lungs, after 

 the method devised by Prof. Martin. Tbe contrac- 

 tions of the heart were registered by means of a Fick 

 spring manometer connected with the cavity of the 

 right ventricle, and the time relations of the beat 

 were determined by Cduipaiiiig this curve with the 

 simultaneous tracing of a tuning-fork vibr.atlng fifty 

 times a second. — (Stud. biol. lab. Johns Ilojik. uiiiv., 

 ii. 453.) w. u. u. [584 



ANTHROPOLOGY. 

 Tattooing among civilized people. — Last De- 

 cember Dr. Koberl Fletcher read a paper on tattooing 

 among civilized people, wliieh he is now publishing. 

 The custom presents itself from two points of view, — 

 the medico-legal and the anthropological. Compared 

 with the elaborate tattooing of many savage tribes, the 

 designs which sailors, soldiers, and, above all, crimi- 

 nals, have imprinted on their persons, are trivial or 

 offensive in subject, or clumsy in execution. In 1S69 

 Berchou made several reports to the French govern- 

 mt-nt on tattooing among sailors and criminals, and 

 published a work entitled ' Histoire m^Jicale du ta- 

 touage.' At the meeting in Algiers in ISSl, of the 

 French association for the advancement! of science, 

 Magltat exhibited a chart showing the geographical 

 distribution of tattooing, according to methods, as 

 follows: 1. By pricking; 2. By simple incision; 3. By 

 ulceration or burning; 4. Flspodermic tattooing; 5. 

 Mixed tattooing. Among the distinguished observers 

 of this practice are Cesar Lombroso of Turin, and 

 Dr. A. Lacassagne of Lyons. Lombroso publishes a 

 chapter on tattooing in his ' L'uomo deliquente,' and 

 Lacassagne is the author of a volume entitled 'Lea 

 tatoiiages, fiiuile antbropologique et m^dico-l^gale.' 

 He gives a table showing the parts of the body oper- 



