Miscellaneous. 465 



urinary organs, the hyoid apparatus, and especially the branchiae will 

 be formed. The circulation which took place in the umbilical 

 vesicle, a provisional respiratory organ, will cease. New vessels will 

 appear and others will become atrophied ; the chorda dorsalis and 

 the sheath which surrounds it will become solidified to produce the 

 bodies of the vertebrae. The true or permanent fins, at first reduced 

 to two pectoral palettes which the animal agitates very rapidly, will 

 originate in the interior and at the expense of the embryonic caudal 

 membrane or fin ; finally brilliant iridescent scales will cover the 

 body of the animal, which, from this moment, wUl appear under 

 the form belonging to the adult age. 



Such is, briefly, the series of changes which will be manifested at 

 various intervals in our new-born fish. These changes are exactly 

 of the same nature and at least as considerable and numerous as 

 those which occur in Petromyzo^i PJaneri, in the Insects, or in the 

 Crustacea {Caridina Desmarestii, Cancer pagurus, &c.). Formation 

 of new parts (mouth, intestine, branchial apparatus, geuito-urinary 

 apparatus, permanent fins, vertebral arches), disappearance of parts 

 previously existing (vitelline vesicle and its vessels, embryonic caudal 

 membrane), modifications in the form of the body, in that of the heart 

 and in its structure (which was at first entirely cellular), in the eyes 

 (originally destitute of pigment and becoming movable instead of im- 

 movable as at first), »fec. &c. l^ow formation, disappearance, and modi- 

 fication are the three essential modes which are included, according to 

 Duges, in that very complex operation that we call metamorpliosis ; and 

 if I am not deceived, the embryogeny of the Maci'opoda has displayed 

 them to us. 



To accept the reality of metamorphosis in the case of the grass- 

 hopper for example, and the other Orthoptera or Hemiptera which 

 quit the egg with all their parts except the ivings, and to refuse to 

 believe in this phenomenon when we have to do with osseous fishes 

 such as the perch or the Macropoda, would, it seems to me, be to show 

 a deficiency of logic and to close our eyes voluntarily against 

 evidence. — Comptes Bendus, Sept. 30, 1872, p. 766. 



On the Habits of Terebratula^, or Lamp-shells. 

 By Dr. J. E. Gkat, F.R.S. &c. 



Mr. Davidson informs me that the shell I have named Terebratida 

 truncata in the ' Annals and Magazine of Natural History' for 1872 

 (x. p. 152) is what is now called Kraussia rubra (T. r-ubra, PaUas). 

 He also informs me that " Mr. Jeffreys found a number of specimens 

 of Terebratidina caput-serpentis attached to seaweed ; and he believes 

 some forms of Argiope that occur in the Mediterranean likewise affix 

 themselves co seaweed." 



On referring to Mr. Jeffreys's ' British Conchology,' ii, p. 15, he 

 says, " T. caput-serpentis is attached to stones, old shells, and occa- 

 sionally to small seaweeds and other substances ;" and Mr. Davidson 

 informs me that " Prof. E. Forbes had found some small specimens 



