NOTES O.N MAKSII'I U.IAN ANATUMV. 



trcmcly vascular, tontain iil; a small proptjilion of erectile 

 tissue, and is fairly abundantly supplied with ners'e tissue. 

 It is partially divided l»y epithelial septa similar to those 

 of the clitoris. 



Sections through the caudal portion of the clitoris a 

 little in advance of the apex show that the organ is here 

 divided into three lobes by two complete septa. Each 

 of these septa is caudally converted into the shallow 

 grooves separating the three free apical portions of the 

 organ. These septa, as will be shown later, correspond to 

 the lateral septa, such as occur, e.g., in Phascolarctos (3, 

 PI. 4, Fig. 4). This portion of the clitoris is shown in 

 Fig. 5. From each of these main lateral septa passes off 

 into the lateral clitoris lobes, secondary lateral septa, each 

 passing ventro-laterally to end in a slight swelling, making 

 the septum somewhat club-shaped. No such secondary 

 septa occur in the central lobe. ]n this central portion 

 we find in the mid-line extending upwards a short distance 

 from the ventral clitoris wall a short epithelial septum re- 

 presenting what is left of the criginal median septum of 

 the clitoris which is found in tlio pouch young of this 

 genus, and which persists in those marsupials (e.g., Pera- 

 meles, vide 5. p. 56, PI. .'), Fig. 9), in which the clitoris 

 i-emains in the adult in a somewhat primitive condition. 



The clitoris wall is seen to be composed of a stratified 

 epithelium continuous with that of the cloaca. This 

 epithelium consists of a basal layer of cells with large 

 nuclei arranged at right angles to the surface, these being 

 overlain by four or five layers of flattened pavement cells. 



The lobes of the clitoris are extremely vascular, con- 

 taining numerous large thin-walled vessels. Where v.ho 

 rudiment of the median septum appears an alteration oc- 

 curs in the main lateral septa. Each of these consists 

 of two portions a dorsal portion, and a ventral, the divi- 

 sion between being marked by the oiigin of the secondary 

 lateral septum. A change takes place in such a way that 

 the ventral portion gradually disappears, leaving only the 

 dorsal portion in connection with the secondary lateral 

 septum. F(;v a time th'j lowest portion of the ventral 

 divisioji persists, but in time also disappears, the clitoris 

 possessing now two diverging septa composed mainly of thi' 

 »econdarv lateral septa, which now extend somewhat in 

 length ventro-laterally. Round the ends of these septa 

 til-' vessels of each lobe enter into communication. 



