349 



water pores on the margin of the disc, in Echinoderms, 

 especially in Echinarachnius, were different from the ambul- 

 acra! tubes and pores. 



In regard to the resemblances of MediiscB and Echinoderms, 

 he would say that SciUella, for instance, is only a jelly-fish, in 

 whose substance lime is deposited. Both have the water-tubes ; 

 only in Medusce^ there is a closed system, while in Echinoderms 

 the water is introduced through open pores. The shell of 

 Echinoderms is then a modification of the gelatinous body of 

 Medusce, by the deposition of lime in the jelly. 



Prof. Jeffries Wyman gave an account of dissections of 

 some of the blind -animals from the Mammoth Cave, Ken- 

 tucky. 



In examining the fishes, his results were nearly the same as 

 Muller's, who found rudiments of eyes, or black points of pig- 

 ment, but no cornea, no optic nerve, no ocular contents. Dr. 

 Wyman, however, found no eye spots. As the small filaments 

 of the fifth pair of nerves could be distinguished, he is confident 

 the optic nerve could not have escaped his careful examination, 

 if it had existed. The optic lobes existed ; according to the 

 general rules of physiology these should not exist, as they bear 

 a strict relation to the sense of sight, which receives its nerve 

 from them ; both morbid and comparative anatomy show that 

 disease of the eye impairing or destroying vision, or a naturally 

 deficient sight, are accompanied with a corresponding diminution 

 or atrophy of the optic lobes. Here the optic lobes were not so 

 large as in the allied fishes, but yet they were of good size, and 

 nearly as large as the cerebral lobes. This fact would lead us to 

 inquire if these lobes are the seat of any other function than that 

 of sight. 



In the craw-fish, there is the eye-pedicle, but there are no 

 facettes ; only simple integument covered with hairs. The 

 crickets, with long antennae, have as well developed eyes as 

 crickets living in the light. 



Mr. Desor made some remarks on the methods pursued 

 by the Indians for preserving their venison and pemmican 



