7171 Unusual Modes of Gestation in 



alarmed went at once into the grass and thick bushes. One of my 

 companions, Mr. John Green, and myself succeeded in capturing some 

 specimens, which, as we were just leaving the village, were placed at 

 once in alcohol. In one instance the larvae were retained permanently 

 adherent to the back of the parent, in consequence of the coagulation 

 of the mucus covering the surface of the body, and are still preserved 

 in the Museum of Comparative Anatomy at Cambridge. The young, 

 from twelve to twenty in number, were collected upon the back of the 

 mother, their heads directed towards the middle line : they were about 

 three-fourths of an inch in length. No limbs were developed, though 

 in some of them the rudiments of a leg existed in the form of a small 

 papilla on either side of the base of the tail. No especial organ was 

 found to aid them in adhering to the back of the parent; the adhesion 

 may have been effected by the mouth. This is rendered probable by 

 the fact that all of them had the mouth in contact either with the 

 skin of the parent or with that of another larva. A viscid mucus 

 covering the integuments undoubtedly assisted in some measure to 

 bring about the same results. However this may be, they retained 

 their places perfectly well, and were not displaced when their mother, 

 closely pursued, carried them through the grass. 



On dissection of the young nothing was found materially different 

 to conditions of the larvae of other Anoura. The external gills had 

 disappeared, but were replaced by internal ones, which were arranged 

 as usual on three hyoid arches. The development of the lungs had 

 commenced, and these were represented by a slender conical mass of 

 cells, but not permeable to air. The mouth was provided with finely 

 denticulated horny jaws, and the intestinal canal was shorter and less 

 spirally convoluted than in ordinary larvae of frogs and toads. The 

 stomach was not so much developed as to be distinguished from the 

 rest of the intestine ; but this last, after passing the liver, was some- 

 what dilated, and contained, as was shown by the microscope, large 

 quantities of yelk-cells which had not been absorbed, and which were 

 adherent to its walls. 



We have here, then, a larva, in all the details of its structure, espe- 

 cially in the existence of gills and of a flattened tail, adapted to aquatic 

 locomotion and respiration, yet passing a portion of its time at least 

 on the back of its parent, and at a distance from the water. 



I was not able to ascertain whether the eggs were primarily de- 

 posited in the water or not, but it is well known to some of the colo- 

 nists that after the larvae have reached a certain degree of development 

 they are carried about in the manner just described, and they do not 



