226 Prof. T. Thomson Flynn on Iteproduclive 



nocturnul in liabits, found almost invariably (in southern 

 Tasmania) in those eucalypts known familiarly as " pepper- 

 mint gums," on the succulent terminal twigs of which it 

 fi'cds. It is ])articularly hard to trap, and is obtained 

 generally by "mooning" — that is, by shooting on moon-li,>;ht 

 niglits in the way described by Broom for Trichosums vulpe- 

 cnla*. In this way it is quite possible for a good shot, with 

 a well-trained dog, under favourable conditiotis to get a bag 

 of some four or five dozen animals in one night. Tiio dog's 

 share in the hunt is to scent out the trees in which the 

 animals are feeding. 



Pseudochirus breeds during the whole winter from May to 

 August. I have, on one occasion, found early segmenting 

 eggs in the last week of August, and it is possible that 

 pregnant specimensmay occasionally occur early in September. 

 It is common cnougii, however, to get pseudo-pregnant 

 females in the latter monih. Having done no collecting in 

 the summer months, I am not able to say whether there is a 

 summer breeding-season, but, judging from statements made 

 to me by hunters, I think it quite likely. 



The female organs of Pseudochirus are, as might be 

 expected, similar to those of Trick siinis. The lateral 

 vaginal canals are quite conspicuous, especiall}^ during 

 " heat," and serve for the transmission, in coilu, of tiie semen. 

 In Pseudochirus a\so, us in Trichosurus, as Hill as shown f, 

 parturition takes place through a pseudo-vaginal passage. 



Detailed observations on marsupial development so far 

 published refer almost entirely to two polyprotodont genera — 

 Dasyiirus viverrinus and Dideljyhys virginiana. In both of 

 these, as shown by Hill J, Hill and (J'Donogliue§, and 

 Hartman |1, there is a lavish over-production of young, 

 reduced by abnoimality and mortality to more reasonable 

 proportions. Even so, the amount of over-production is 



* Broom, R., " A Contribution to the Development of the Common 

 Phalan<rer/' Proc. Linn. Soc. N.S. \V. 1898; see also Geoffrey Smith, 

 ' A Naturalist in Tasmania' (Macmillan, London, 1909). 



t Hill, .T. P., " Contributions to the Morphology and Development of 

 the Female Urog-enital Organs in the Marsupialia. — V.," Proc. Linn. 

 Soc. N.S.W. (1900). 



;J; Hill, J. P., " Un the Fcetal Membranes, Placentation, and Partu- 

 rition of the Native Cat {Dasyunis viverrinus)^'" Anat. Anz. vol. xviii. 

 (1900). 



§ Hill, J. P., and O'Donoghue, C. H., " The Reproduction Cycle in the 

 Marsupial Dctsijurus viverrinus,''' Quart. Journ. Micr. Sc. vol. lix. (1913). 



II Ilartman, C. G., "Studies in the Development of the Opossum 

 Didelphya virr/inidna,'' Journal of Morphology, vols, xxvii. and xxxii. 

 (1916 and 1919). 



