322 



MARSUPIALIA. 



has begun to be formed. Qy. Will the foetus 

 seize the larger nipple as the readiest, or be 

 directed to another more proportionate to the 

 size of its mouth ? 



" Oct. 4th. 38th day. The keeper has 

 observed the female putting her nose into the 

 pouch, and licking the entry. She was exa- 

 mined at six in the evening ; there was a slight 

 increase of the brown secretion; the nipple 

 formerly in use has diminished one-third in 

 size ; the other nipples indicate no appearance 

 of approaching parturition. 



" Oct. 5th. 39th day. The keeper exa- 

 mined the pouch at seven this morning, and 

 found there the young one attached to a nipple. 

 On being made acquainted with this fact I re- 

 paired to the Zoological Gardens, and examined 

 the pouch. The new-born kangaroo (Jig. 140) 

 was attached to the left superior nipple (fg. 140, 

 ), to the point of which it adhered pretty 



Fig. 140. 



New-born fcetus and left nipples, Macropvs major. 

 firmly. It measured one inch from the mouth 

 to the root of the tail, was quite naked, and co- 

 vered by a thin semitransparent vascular integu- 

 ment; the place of attachment of the umbilical 

 chord was obscurely indicated by a longitudinal 

 linear cicatrix. The fore-legs were longer and 

 stronger than the hind ones, and the digits were 

 provided with claws ; the toes were developed 

 on the hind legs ; the body was bent forward ; 

 and the short tail tucked in between the hind 

 legs. This little animal breathed strongly, 

 but slowly ; no direct act of sucking could be 

 perceived. Such, after a gestation of thirty- 

 eight days, is the condition of the new-born 

 young of a species of Kangaroo, of which the 

 adult, when standing erect on his hind feet and 

 tail, can reach to the height of seven feet. The 

 birth having taken place in the night, the mode 

 of transference of the young to the pouch and 

 nipple was not observed. 



The hypothesis of an internal passage from 

 the uterus to the pouch countenanced by 

 some imperfect anatomical observations on the 

 course of the round ligament to the abdominal 

 ring, and the continuation thence of the cre- 

 master to the posterior part of the mammary 

 gland, together with the primitive inverted 

 condition of the nipple is wholly refuted by 

 more exact observations of the conditions of 

 these parts. I was chagrined at the loss of so 

 favourable an opportunity of determining, ex 

 visii, this interesting part of the problem ; for 

 it had been my intention, if the symptoms of 

 approaching pregnancy had been more marked, 

 to have established a night as well as day-watch 

 over the female; but by placing perhaps too 



much reliance on the observations on the preg- 

 nant kangaroo recorded in the 9th volume of the 

 Annales des Sciences, in which the duration 

 of four months is assigned to the uterine gesta- 

 tion of this species, 1 had not anticipated so 

 speedy a termination of that process as resulted 

 from my experiment. 



In order, however, to remedy, as far as might 

 be, this omission, it occurred to me that if the 

 young kangaroo were detached from the nipple 

 and deposited at the bottom of the pouch, any 

 actions of the parent, by which its original 

 transference from the uterus to the nipple had 

 been aided or effected, might be instinctively 

 repeated, and thus an insight be gained into 

 their nature. As, therefore, the experiments of 

 Messrs. Morgan and Collie seemed to show that 

 this might be done without necessarily causing 

 the death of the young one. I performed the 

 experiment with the sanction and assistance of 

 Mr. Bennett, then Secretary of the Zoological 

 Society. 



" Oct. 9th. I examined the pouch of the 

 female, and found the young one, now four 

 days old, evidently grown, and respiring vigo- 

 rously ; it adhered more firmly to the nipple 

 than was expected, requiring a continued 

 gentle pressure to detach it : when that took 

 place, a minute drop of whitish fluid, a kind 

 of serous milk, was expressed from the nipple. 

 No blood followed, nor anything to indicate 

 a solution of organic continuity; the extremity 

 of the nipple was small, not swollen as in Mr. 

 Collie's case. The young one moved its extre- 

 mities vigorously. It was deposited at the bot- 

 tom of the pouch, and the mother was left and 

 then carefully watched. Soon after this was 

 done she seemed uneasy, was often scratching 

 the exterior of the pouch, and every now 

 and then dilated the cavity with her two fore- 

 paws, grasping the sides of the aperture, and 

 pulling them in contrary directions, just as in 

 drawing open a bag; she then inserted her 

 muzzle pretty deeply into the pouch, moving 

 her head about as if to lick oft something from 

 the interior, or perhaps to move the little one. 

 She kept her nose in the pouch sometimes for 

 half-a-minute. I never observed her to put 

 her fore-legs, or either of them, in the pouch ; 

 they were always occupied in keeping open the 

 mouth of the pouch, while she was at work 

 with her mouth within it. She generally con- 

 cluded by licking the mouth of the pouch, 

 and occasionally she stooped down to lick the 

 cloaca, which she could reach with ease. 

 When she scratched the outside of the pouch it 

 seemed as if to push up something that was in- 

 side towards the aperture. These actions she 

 repeated at short intervals for about an hour; 

 she then lay down and appeared quiet. She 

 had also lain down in the intervals of the above 

 operation, but during that time never meddled 

 with the pouch ; when stimulated to do so by 

 some uneasy sensation, she always rose upon 

 her hind feet, and then inserted her muzzle 

 alternately into the pouch and vulva. Observing 

 the freedom with which she could reach both 

 these parts, I was led to believe that the mode 

 of removal of the young from the vulva to the 



