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reception of the Mounirematovs Quadrupeds of New Holland, and of 

 separating them altogether from the Mammalia, arose cliitfly from 

 the supposition of the totai absence of a niammary apparatus in them. 

 This circumstance was at the šame time regarded as a strongproof 

 of an essential difference in their mode of producing the young : and 

 it was inferred that the latter, in the absence of the lacteal nourish- 

 ment, mušt have derived the materials necessary for their develop- 

 ment from some store of nutriment analogous to the yelk of the em- 

 bryo in the oviparous and ovoviviparous tribes. 



" But the converse of this proposition, that a mammiferous animal 

 mušt necessarily be viviparous, by no meaiis follows. The develop- 

 nient of an animal may be carried on to a certain degree either in 

 the oviparous or ovoviviparous mode of generation, and yet after in- 

 cubation or birth, additional store of nulriment may be required from 

 the parent in order that the processes of organization may be 

 completed to the extent necessary to enable the young animal to 

 gain a subsistence by its own exertions. Indeed, when we consi- 

 der how long, in many of the orders of Birds, the unfledged young 

 are totaliy dependent on their parent for their nutriment ; that this nu- 

 triment, though in general foreign matter, collected with much indus- 

 try and freąuently at great risk, yet is sometimes, as in the Pigeon, a 

 secretion from the parent's body ; and \vhen vve further refiect that 

 geiieration in the Marsupiaia is essentially of the ovoviviparous kind, 

 — vve shall have no difficulty in reconciiing ourselves to the considera- 

 tlon of the Monotremata as oviparous or ovoviviparous, and at tlie 

 šame time as mammiferous, animals. 



" With respect to the Ornithorhjnchus, it seems incontrovertible 

 that the apparatus discovered by Meckel is trulv mamraary, and exe- 

 cutes the importanf function of providing the lacteal nutriment for 

 the young. Nevertheless, this discovery leaves us just as much in 

 the dark as vve were before respecting its mode of generation, and 

 eąually dependent on the exertions of those naturalists who may 

 have the good fortune of observing facls in the living animal respect- 

 ing this most interesting and important subject. lt is obvious also, 

 that the discovery of the mammary glands in the other monotrema- 

 tous genus, although highly confirmatory of their accordance vvith 

 the ręst of the Mammalia in the characteristic function of lactation, 

 yet by no means renders less necessary an unremitting attention to 

 every habit of the living animal which may elucidate the processes of 

 generation. 



" In the meanvvhile, hovvever, it aftbrds me much pleasure to be 

 able to lay before the Committee preparations of the mammary glands 

 from the Echidna Hystrix, vvhich, as the follovving description will 

 shovv, afford an additional instance of the close affinity subsisting be- 

 tvveen it and Ornithorhyiuhus, notvvithstanding the great dissimila- 

 rity existing betvveen them in external form and in the nature of 

 their integuments. These glands were discovered in a female spe- 

 cimen not quite arrived at maturity, and vvhich therefore in all pro- 

 bability had never bcen imprcgnated. They are conseąuently vtry 

 small, as compared vvith those vvhich have been observed in Orni- 

 thorlnjnchun, but are prccisely analogous in numbcr, form, composi- 



