No. 2.] ON THE GUSTATORY ORGANS. 19I 



tiuiis. In other genera, as Phalangista, Belideus, Acrobates, 

 Bettongia, PJiascolarctos, and DidclpJiys, the posterior papilla 

 follows more closely the type characteristic of higher animals, 

 while the anterior pair are still in a transitional stage of develop- 

 ment. In PJuiscoIoniys, Pcramelcs, and some species of Didel- 

 pJiys, all three papillae are closely allied to the type common to 

 higher animals. 



Although the lateral gustatory organs have not been detected 

 in all marsupials in which a search for them has been made, 

 they have been found in a sufficient number of species to render 

 their existence in all scarcely open to doubt. In HalmaturuSy 

 according to Poulton, the organ consists of a row of gland ducts, 

 in the walls of which scattered bulbs are developed. In Macro- 

 pus, Petrogalc, and PJiascolarctos they are more advanced, the 

 ducts opening at the bottom of depressions. In Perameles the 

 organ consists of a single epithelial-lined furrow, in the walls of 

 which are several tiers of bulbs. In Phalangista, Belideus, 

 Acrobates, and Didelphys the organs are less simple in struc- 

 ture, and the ducts open at the bottom of the furrows as in the 

 higher mammals. 



Edentata have but two circumvallate papillae. The posterior 

 papilla has disappeared, to reappear in the Castoridae, Sciuridae, 

 Pteropodidae, and Quadrumana. They are on the same trans- 

 verse line, and may be considered as representing the anterior 

 papillae of the Marsupialia. While some species show a very 

 decided advance in all, or nearly all, the points which the papillae 

 of the two orders have in common, other species appear to fol- 

 low closely the marsupial type. In Dasypus peba they resemble 

 in the main those of higher animals. In Chlamyphorus truncatzis 

 they approach quite closely the marsupial type, the resemblance 

 between them and the anterior papillae of Belideus and PJialaji- 

 gista being very marked. The papillae of Dasypus villosus 

 appear to hold an intermediate position, both types being repre- 

 sented, although more or less modified. This species was the 

 only one in which I detected lateral gustatory organs, although 

 they are doubtless present in the others. The organs were 

 wholly unlike any yet described except those of Procyon lotor. 



Bulbs appear to be wanting in the larynx of both the Marsu- 

 pialia and Edentata. Further research, however, may show 

 their existence in this region, although it is not unlikely that 

 their appearance here is more recent. 



