1883.] TONGUES OF THE MARSUPIALS. 619 



continued into two horns which pass anteriorly round the papilla 

 outside the ring of secondary hair-Hke papillae. As the section is 

 taken at successively higher levels, these horns are prolonged further 

 and further anteriorly until they seem to meet and enclose the 

 whole papilla. (Thus fig. xxiii. Plate LV. represents a section taken 

 rather low.) The cornified cells of the hooks are remarkably hard, 

 so that the razor cuts them with a very audible sound and with much 

 detriment to its edge; they remain bright yellow after treatment 

 with logwood. A vertical longitudinal section through one of these 

 papillae is drawn in fig. xxii. Plate LV., and it shows the great size 

 and strength and the curvature of the posterior hook ; it also shows 

 the thin anterior corneous layer first appearing where the hook becomes 

 clear of the main papilla. Both these figures alluded to are semi- 

 diagrammatic, and are in some points the probable interpretation of 

 very doubtful appearances due to changes in the tissues. This 

 region is very interesting, for it shows how the slender elements of 

 the coronate papillae have been modified to perform the tough work 

 of the horny filiform papillte of higher animals. It is obvious that 

 the strong posterior hooks would first meet any object, and would 

 be obliged to do practically all the work, when tlie tongue was drawn 

 backwards in licking. 



The coronate papillae above the tip, in front of this peculiar region, 

 are of more regular form; but the posterior secondary papilla (and 

 occasionally one beside it) is more strongly cornified and larger than 

 the others. The cornification also tends to pass anteriorly round 

 the outside of the other secondary papillae as two horns. In these 

 points there is a transition towards the modified papillae described 

 above, but the characters increase very suddenly at the limits 

 (posteriorly also) of the peculiar region. " The secondary papilla in 

 the rings are not numerous, 6-8 being common ; they are much 

 recurved : the papillae are small and numerous, i. e. about 72 to the 

 square millimetre. There are no isolated hair-like papillae. The 

 coronate papillae just in front of the anterior circumvallate papillfe 

 are rather small and closely packed (about 60 to the square milli- 

 metre) ; they are round or oval, and some irregular in shape. A 

 few are remarkably elongated antero-posteriorly (see fig. xxiv. 

 Plate LV., in which the effect may be increased by a slight obliquity 

 of section, but is remarkable anyhow) : such elongated papillae are 

 doubtless formed by longitudinal coalescence, as I have seen traces 

 of a central constriction, and the number of secondary papillae is 

 about twice the usual number (8-10). There is no special size or 

 cornification in the posterior secondary papillae. Isolated hair-like 

 papillae are not present. The upper cells of the papillae stain deeply, 

 as has been described in Perameles ; in fact these posterior coronate 

 papillae are very similar to those of Perameles. They are recurved, 

 but less than the anterior papillae ; they are not of the tall slender 

 type like the posterior coronate papillae of Belideus, but are more 

 Hke the posterior type of Perameles, differing from these in the 

 greater symmetry of the ring of secondary papillae when cut hori- 

 zontally. The modified papillae described above are transitional 



