fRANSACTiONS OF" SECtlON D. 785 



2. Dl*opsy of the central cavities of the train or of the meninges Is remarkatle 

 for its absence. The cerebral lobes are more or less united, but they may attain 

 a very fair degree of development. Pineal growths are present as in the normal 

 condition, 



3. Trabeculm cranii of full length are present, but they bend downwards so as 

 to lie below the cyclopean eye or pair of eyes. They are closely fused together 

 anteriorly to form a single median bar, the appearance of which suggests that in 

 this region they have never been separate. 



4. In some of the specimens examined cyclopia is associated with absence of 

 the mouth opening and great shortening of the lower jaw arch. 



In these cases the infundibulum and the whole pituitary body are absent, 

 the basal masses of the mid-brain are more or less fused together, the optic nerves 

 are rudimentary or absent, and the eyes, though they have a well-developed 

 retina and choroid, have no choroidal fissure. The auditory labyrinths and capsules 

 on either side as well as the suspensorial cartilages remain, however, almost as 

 widely separate as in the normal condition. 



On some Causes of Brain-configuration in the Brain of Selachianst 

 By Professor R, Burckhardt. 



7. On the Syatematic Value of the Brain in Selachians, 

 By Professor R. Burokhaedt. 



8. On some Points in the Life-History of the Littoral Fishes. 

 By Professor W. C. McIntosh, F.R.S. 



No group of marine fishes is better fitted for the demonstration of the great 

 mortality which ensues between the period of the deposition of the eggs and the 

 attamment of the adult condition than the littoral' fishes, such as the shanny, 

 viviparous blenny, sea-scorpion, lumpsucker(;>«rfm), gunnel, fifteeu-spined stickle- 

 back, and the five-bearded rockling. The adults, for instance, of the shanny can, 

 as a rule, be readily located in the pools between tide-marks on rocky shores. The 

 adult female deposits a considerable number of eggs in small rocky caverns, and 

 the pelagic young abound in the tidal pools in August and September. As they 

 increase in size they become fewer, not by spreadincr themselves in the ocean or 

 by taking advantage of new sites amongst the rocks, but by steady diminution 

 from the attacks of other predatory forms. One or two adults alone survive in 

 each suitable rock-pool. In the group under consideration the conditions of the 

 species are various, the majority, however, having demersal eggs, which in the 

 case of the gunnel are protected by the parents, and in the fifteen-spined stickle- 

 back are sheltered in a nest, whilst the reckling has pelagic eggs, and the vivi- 

 parous blenny produces living young fully two inches in length. The result is 

 nearly the same in each case, for the adults do not, as a rule, vary much from 

 period to period. A comparatively large number of eggs and young are necessary 

 to maintain the species, even though in our country there is no systematic capture 

 of any of them either for food or pleasure. 



SATURDAY, SEPTEMBER 8. 



The following Reports and Papers were read :— 



1. Report on the Physiological Effects of Peptone and its Precursors 



when mtrodticed into the circulation.— B ee Reports, p. 457. 

 1900. 3 B 



