466 Miscellaneous. 



" My deak Sir, — Natural history has been so little my study that 

 I should not have presumed to claim a place among observers if 

 you had not encouraged me to believe that a record of an observa- 

 tion which I made some time since on the habits of the Balanus 

 may possess some interest among naturalists. I had at that time a 

 small marine aquarium, in which I often kept specimens of Serpulae, 

 Sea-aneniones, Balani, &c. It was placed on a shelf, where it had 

 a good through light, and any movements or actions of its occupants 

 could be well seen. On one occasion I watched for some minutes a 

 proceeding in a group of the common Balanus, which I have no 

 doubt was the process of impregnation. A long flexible thread-like 

 instrument, of at least double the length of the cirrus, proceeded 

 from near the centre of one of the creatures, and was waved around 

 as if in quest of something. On meeting the cirrus of some of the 

 surrounding animals this was eagerly seized and inserted into them 

 successively, all the animals during the operation giving evidence 

 of a high state of excitement. I regret that, from not being aware 

 at the time that the observation might possess any value, I did not 

 make a record of it, nor did I observe the details with as much 

 minuteness as I should otherwise have done ; but I have no hesi- 

 tation in asserting that the above is substantially correct, and I 

 should think the observation might be easily repeated if desired. 



Yours truly, E. B." 



Calcareous Sponges, By H. J. Carter, P.R.S. 



With reference to the statement in the 'Annals' (vol. iii. p. 16, 

 1869) that the spicules of Qrantia ciliata itc. which I had examined 

 had no central canal, I now find, by subsequent examination, that 

 a trace of something like one may often be seen towards the base 

 of the straight arm of the triradiate spicule ; and perhaps this may 

 be patent here and there ; but it is as often represented by a cast, 

 probably of the same material as that composing the spicule, pro- 

 jecting from its fractured end, and this only in the fresh state, for 

 the heat of mounting in balsam destroys it, while for the most part 

 there is no trace whatever that I can observe. Nor does the calca- 

 reous spicule present the concentric lamination seen in the siliceous 

 one, although both break with a similar conchoidal fracture. Per- 

 haps the material, and not the organology, may account for these 

 differences. At any rate, you have only to look for the axial canal 

 in the siliceous spicule to see it, whereas in the calcareous one you 

 can only fancy its existence here and there, in Orantia ciliata. 



Budleigh-Salterton, May 28, 1869. 



Are Unios sensitive to Light ? By Isaac Lea. 



In the March No. of this Journal, p. 286 ('Annals,' May 1869, 

 p. 399), Mr. C. A. White heads an article with "Are Unios sensitive 

 to light? " He then gives some experiments which he instituted on 

 the subject, and he seems to be under the impression that his obser- 

 vations were entirely new. 



If your readers will turn to the ' Proceedings of the Acad. Natural 

 Sciences of Philad.' for 1857, they will find a communication from 

 me where the subject of touch, hearing, and sight in the Unionidai 



