'Die larynx of the Marsupialia consists of a cricoid, thyroid, and arytenoid cartilages and an epiglottis. The latter is always remarkable for its large size, and generally for its emar ginate apex. There is no muscle passing from the epiglottis to the tongue; its base is con nected in the Kangaroo by a triangular fascia to the body of the os hyoides and the greater cornea; and a small muscle passes from the middle part of the body of the os hyoides to the dorsum In the Phalangers the epiglottis is broad and short, and with a hifid apex. In the Pe rameles and Phascogale the sides of the broad and short epiglottis are attached to the apices of the arytenoid cartilages, retaining thus much of its early condition, which will be adverted to in the account of the peculiarities of the mam mary ftetus.
In the Perameles lagotis I found on the base of the tongue in front of the epiglottis a small sacculus of mucous membrane, which communicated by a regular symmetrical cre scentic aperture, situated between the body of the os hyoides and the thyroid cartilage, and continued down in front of the thyroid cartilage: the surface of the cavity was smooth and lubri cated, and it seemed to be for the purpose of facilitating a hinge-like motion between the thyroid cartilage and the body of the os liy oides.
The thyroid cartilage is convex externally and protuberant in the Phalangers and Koala, but offers no particular modification in other Mar supials. The base of the arytenoid cartilages is broad in the antero-posterior direction, and the chordm vocales short and feebly developed. The Marsupials have little or no voice : the Wombat emits a guttural hissing sound : the Dasyttrus ursinus a snarling growl or whine : the Thylacine is described as uttering a short guttural cry. I have never heard a vocal note of any kind from the Kangaroos, Potoroos, I'e taurists, Phalangers, or Perameles.
Renal system.—The kidneys present a simple conglobate external form in all the Marsupials, as infig.134, o, o, and in their structure and po sition in the abdomen agree with the Mamma lian type of structure.
In the Maeropus Parryi the kidneys are situated six inches above the brim of the pelvis, and lying in the same transverse line: they have the same relative position in other Poephaga.
In the Koala the right kidney is higher by its whole length than the left. In the Dasy uri nuterurus and viverrinus, the right kidney lies half an inch higher or in advance of the left in this carnivorous genus a few branches of the renal veins are distributed upon the sur face of the kidney, but not in the same pro portion or with the beautiful arborescent dis position characteristic of the kidneys of the Cats, Suricates, and IlyTna. In a Dasyurus
maerurus weighing three pounds eight ounces, the two kidneys weighed thirteen drachms. In a Phafangista vulpina, weighing five pounds three ounces, the two kidneys weighed only ten drachms.
The substance of the kidney is divided into a cortical and inedullary part; the former is generally a thin layer. The tubuli uriniferi terminate on a single mammilla which projects into the commencement of the ureter in the Opossums, but does not extend beyond the pelvis of the kidney in the Kangaroos. In the Kangaroos the medullary substance forms several lateral abutments to the base of the main mammilla.
The supra-renal glands generally present the relative position and proportions to the kidneys represented in the Kangaroo, at fig. 134, p. They are, as in most of the smaller quadrupeds, less flat than in man : the right body generally adheres to the coats of the vena cava, and the left to the renal vein. In the Dasyures the ex ternal stratum is light-coloured ; this surrounds a dark-coloured layer, and then there is a light coloured central part, but no cavity.
The ureters terminate at the back of the neck of a muscular and pendulous urinary bladder (t), which only exhibits a trace of urachus at the middle of its anterior part in the young marsupial, while in the maternal pouch.
Male organs of generation.—The testes, which are still abdominal at the time of birth, descend, soon after the fcetus is transferred to the pouch, into the external pedunculate pre penial scrotum ; the canal of communica tion between the abdominal cavity and the tu nica vaginalis is long and narrow, but always remains pervious.
The tubuli testis are relatively smaller than in the Rodentia, but are similarly arranged, the corpus Ilighmorianum being near the surface and upper part, not at the centre, of the gland. The epididymis is large, and generally loosely attached to the testis : in a small species of Kangaroo 1 found the connecting fold of serous membrane half au inch broad. The vasa de ferentia pass from the globus minor along the infundibular muscular sheath formed by the cremaster as far as the abdominal ring, then bend downwards and backwards, and termi nate below and external to the ureters, at the commencement of the urethra (a, fig. 135), on each side a longitudinal verumontanal ridge. There are no vesicula: semivales in any Mar supial quadruped.