HARDWICKE'S SCIEN C E-GOSSIP. 



21 



NOTES AND QUEEIES. 



"Eye-stones."— For the last fifteen years I Lave 

 liad in my cabinet two small specimens of what are 

 vulgarly called "Eye-stones." I am uncertain whether 

 they are familiar objects to a naturalist, and should 

 be happy to learn more about them. All the infor- 

 mation I am able to give as to their history is, that 

 my father obtained them, about fifty years since, in 

 New York, and that they were found in the sand of 

 the coast. They are about the size of half a cherry- 

 stone, and, owing to their form— plano-convex— are 

 used for clearing foreign substances from the eye. 

 The eyelid being raised, the flat side is placed next 

 to the eyeball, and the eyelid suffered to close ; it 

 is then moved on its course, performing the circuit 

 of the eye, clearing all before it. Eor my juvenile 

 amusement they were placed in a shallow vessel 

 containing a small quantity of vinegar. After a 

 few moments, small bubbles appeared on their sur- 

 face, and they suddenly moved about, generally 

 across the vessel. Upon examination they appear 

 to be shells, but yet have no aperture ; so the ques- 

 tion of their inhabitants is curious. The action of 

 the vinegar on the lime of the shells no doubt 

 causrs effervescence, and therefore movements 

 similar to camphor on water. — Theodore Charles 

 Izo'I, Upper Clapton. 



Cladodus mirabilis. — Among the many obscure 

 problems respecting coal-measure fauna? which now 

 wait for and are rapidly receiving solution, there is 

 one having relation to the tooth known as Cladodus. 

 The fishes of the Coal period were of two kinds, — 

 Selachians and Ganoids, the former being, with the 

 exception of their teeth and spines, cartilaginous ; 

 the latter being characterized by opercular and a 

 greater development of osseous structure ; but none 

 of the coal-measure fishes were true teleosts, or 

 bony fishes having endo-skeletons of bone re- 

 sembling the salmon, herring, &c, of the present 

 day. Cladodus teeth evidently belong to the Sela- 

 chians, or cartilaginous fishes ; and hence they are 

 always found scattered and unattached to the ori- 

 ginal matrix. The teeth known as Cladodus have 

 been referred to two different coal-measure Sela- 

 chians, viz. Gyracanthus and Ctenacanthus, but to 

 which of these two they belong is yet included in 

 the long array of unsolved problems which await 

 the investigation of palaeontologists. I am disposed 

 for many reasons to think that the balance of evi- 

 dence is in favour of Ctenacanthus ; my chief 

 reasons for holding the opinion being, that they are 

 not unfrequently found associated with remains of 

 Ctenacanthus, and that, in our Northumberland 

 coal-measures at least, they and the spines of 

 Ctenacanthus are rare : whereas the spines of 

 Gyracanthus are abundant ; and as the teeth con- 

 sist of material equally as imperishable as the spines, 



and were certainly more numerous than the spines 

 in the living animal, it is improbable that the spines 

 should be found in abundance, and the teeth very 

 rarely be discovered. — T. P. Barkas, F.G.S. 



Misprints. — Will you be good enough to correct 

 a slight and very pardonable misprint in my note 

 on "Miltwast," in the December number. It is, 

 however, a misprint which causes my quotation to 

 read nonsensically. Instead of " greenes comming 

 or proceeding from the rate or spleene," it should 

 be "greeues" (griefs). Your printers have also 

 made a little mistake in Mrs. Watney's brief gossip 

 about bees ; in fact, it is not the first time they have 

 made the mistake of printing "W. Holland" when 

 that lady writes— R. Holland. 



Formation oe the Hen's Egg. — Are naturalists 

 agreed as to the way in which the egg is formed in 

 domesticated poultry ? It is asserted that the egg 

 is formed soft within the bird, being blown out in a 

 semifluid state, and hardened by exposure to the 

 air. This to a certain extent must be true. Last 

 year, however, we killed a hen with a fully-formed 

 egg inside her ; the shell, though thin, being quite 

 firm and fit for the table. Weight just under two 

 ounces. This particular egg was never " blown 

 out." Any one may become more or less familiar 

 with the internal processes of a hen. The germs 

 or ovaries may be seen as small as a pea, and their 

 further progress traced in a rudimentary state. I 

 have seen brought on table, from one hen, a suc- 

 cession of five or six at once, graduating in size from 

 a filbert up to a round ball an inch and three- 

 quarters in diameter, without perceiving in them 

 any trace of the external covering, that hard cal- 

 careous matter which we call shell. It would ap. 

 pear that this coating is the last process previous to 

 intended ejection, it may be almost a momentary 

 application. In considering the process, we have 

 certain necessities to deal with, which must have 

 been, so to speak, considered by a provident 

 Creator: 1st. The convenience to the bird of keeping 

 the egg flexible while in process of growth. 2nd. 

 The hindrance & fixed coating would be to the ferti- 

 lizing influence of the male bird. 3rd. The certainty 

 that the supply of matter which forms the shelly 

 deposit is a special desideratum to the bird itself ; 

 and the fact that where suitable food is wanting, 

 the shell is also wanting in consistency, would seem 

 to show that the shell is a separate and local applica- 

 tion. 4th. A certain mottled, uneven, curdling 

 look, often found at one end of an egg, like ill- 

 smoothed mortar, which appears as if it were 

 caused by a sort of unsettled ooze, left at the final 

 closing up of the egg. Can anatomists show if the 

 mitre, which is well supplied with glands, has any 

 province to perform in connection with this pro- 

 cess ? — A. Hall. 



