TRANSACTIONS OF SECTION D. — -DKPT. ANATOMY AND PHYSIOLOGY. 723 



It would be bard to conceive, for instance, of definite magnetic poles in tbe 

 eartb, were tbat mucb less oblate body tban the disc without rotation. It is true 

 tbe magnetic poles of tbe earth do not coincide witb tbe axis of rotation ; but it 

 may be assumed tbat it is by tbe fixing effect of tbe rotation tbat tbe axis of tbe 

 eartb, omitting tbe nutation, is maintained at its given angle to tbe plane of the 

 ecliptic, and tbat thus, though tbe magnetic poles are, of course, in oscillation, 

 yet their direction as regards the fixed stars is a more determinate one tban it 

 would be if there was translation only of tbe eartb without tbe fixing eflect of 

 rotation on one axis. Now, the gyroscope demonstrates tbat a plane of rotation 

 cannot be interfered with without tbe result of determinate precessional movement — 

 movements tbat, if there be rotation, are as likely and as certain to have an object 

 in the microcosm of animal life as they could have in tbe economy of tbe celestial 

 bodies, and, it may be added, as they must in any case have when they are but 

 links in a chain of evolution. 



Tbe author remarks tbat while tbe general course of tbe arteries is direct and 

 but little curved, the parts where we do find curves are mostly in proximity to 

 special organs and in localities where it may be assumed tbat that high function 

 of tbe arterial disc — tbe due stimulation of nerve-tissue — would be in stronger 

 request than in parts such as the ordinary muscular tissue, where there was to be 

 fulfilled a fimction less vital. 



This sudden curve or angle of an artery or its spirality would, judging from 

 what is seen in tbe gyroscope, cause, in the case of tbe simple curve or angle, 

 a renewed, though it might be a reversed, rotation ; and, in the case of tbe spiral 

 artery, a precessional movement in the rotating disc, to which, tbe author repeats, 

 he attaches especial consequence — a view tbat is unavoidable to him when be sees 

 in tbe gyroscope, as one of its phenomena, tbe partial support against gi'avitation 

 of the rotating disc and enclosing ring. 



To sum up the conclusions of tbe author : 1st, rotation imparted by at least 

 two diflerent methods ; 2ndly, rotation preserved from hindrance by repulsion due 

 to a similar electric condition ; 3rdly, rotation utilised in capillaries by its arrest 

 there supplementing the heat due to checked translative motion of discs ; 4tbly, 

 magnetic polarity of iron in discs more defined in direction by plane of rotation 

 of disc being by the rotation more or less fixed ; 5thly, special organs having 

 notably curved or belicine arteries, the former adding to the velocity of rotation, 

 and tbe belicine inducing precessional movement. 



7. Observations on the Incubation of the Indian Python (Python molurus). 



By W. A. Forbes, B.A. 



Tlie only two previously recorded instances of the incubation of their eggs by 

 female Pythons in captivity are those recorded by Valenciennes ('Comptes Rendus,' 

 1841, xiii. pp. 126-133), and Sclater (' P. Z. S.' 1862, pp. 365-368), for P. bidttatus 

 and P. sehm respectively. During tbe summer of 1881 a female of Python 

 mulurus, about 12 feet long, which was kept in the same cage in tbe reptile-bouse 

 in tbe Zoological Society's Gardens as two other Pythons of the opposite sex, one 

 being of the same species, the other P. bivittaius, laid about fifteen eggs, on which 

 she sat steadily for about six weeks, in exactly tbe same manner as in tbe two 

 instances mentioned above. At the termination of that period, as tbe eggs were 

 decomposing and obviously bad, they Avere removed ; some, at least, were fertilised, 

 an embryo about llj inches long having been extracted from one. 



With tbe kind aid of Mr. Zambra, of the well-known firm of Negretti & 

 Zambra, who not only had special thermometers of tbe most approved kind con- 

 structed for this occasion, but also regularly attended himself to help in the obser- 

 vations, a series of observations, about two hundred in number, were taken at 

 regular intervals of 48 or 72 hours, to ascertain the temperature of tbe sitting 

 female, as compared with tbat of the non-incubating male, kept next door under 

 nearly identical conditions of temperature and moisture. Tbe result of these shows 

 tliat, whereas tbe temperature of tbe male, whether taken on the surface or between 



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