| OCR Text |
Show 454 MR. F. E. BEDDARD ON HAPALEMUR GRISEUS. [June 16, to be visible as a fold a line may be traced running to the larger the two lateral folds, to which the attachment of the anangious fold is more closely approximated. Cheirogaleus (Microcebus) smithi.-This Lemur agrees closely with Galago. The median anangious fold arising from the small intestine is very large ; there is only one lateral fold bearing a blood-vessel, which fuses with the median fold; this lateral fold arises behind the small intestine from the ileo-colic mesentery; the same is probably true of Galago, though my specimen did not show it. Of the genus Lemur I have examined the following species, viz. L. brunneus, L. rufifrons, L. albifrons, L. varius, and L. anjuanensis. In Lemur brunneus there are only two folds attached to the csecum ; one of these extends to the very extremity of that appendage, arising not from the small intestine, but from the mesentery behind the small intestine which attaches it to the colon; this fold bears a blood-vessel ; the second fold is very short and apparently completely anangious ; it arises from the small intestine itself and is attached to the first-mentioned fold, so that there is but one line of attachment to the csecum ; the attachment of the second (anangious) fold to the first is for a distance of not more than one fifth of its length. Lemur rufifrons appears to be exactly like the last species in the number and disposition of the mesenteric folds attached to the csecum. Lemur albifrons differs from the last two species only in the reduction of the anangious fold arising from the small intestine. In Lemur varius this fold is still further reduced and has become quite rudimentary. Lemur anjuanensis, as regards the folds (see fig. 3, p. 455), is precisely like Lemur brunneus. As regards the disposition of the folds of mesentery connected with the csecum, the genera mentioned in the present paper appear to fall into three groups :- (1) Hapalemur stands apart from the rest in possessing only the two lateral folds, both of which bear blood-vessels. (2) In Lemur, Galago, and Microcebus (= Cheirogaleus) only one of the two lateral, vessel-bearing, folds is present; in addition to this there is an anangious fold arising from the ileum and inserted on to the lateral fold. (3) In Loris, Nycticebus, and Perodicticus all three folds are present, but one of the lateral folds is generally much more developed than the other. The median frenum may (Nycticebus) or may not (Perodicticus) be attached to the larger of the two lateral folds. It might be supposed that the raison d'etre of the persistence of the median frenum was to assist in preventing the displacement of the csecum ; the short sac-like csecum of Hapalemur, which is without the median frenum, might, on account of its shape and relative size, be less easily displaced or bent than the elongated csecum of Lemur or Perodicticus. |
