Miscellaneous. 493 



other cases it seems to be the natural growth of the specimens. 

 Capt. Carmichael, like some botanists, seems to consider species to 

 depend on the "distinction of the character" that can be assigned 

 for a species, rather than on the distinctness of the structure and 

 economy of the species itself: for it must be well known to all 

 practical naturalists that many species, which are very difficult to 

 distinguish by characters, are nevertheless distinct, while specimens 

 which offer, like Enteromorpha cornucopia, a striking peculiarity 

 in external characters, easily expressed in words, are only accidental 

 or local varieties, which can, by mere transplantation, be converted 

 into the presumed species. 



On the Liability of Shells to Injury from the Growth of a Fungus. 

 By the Rev. H. H. Higgins, M.A. 



It has often been observed that shells kept for a considerable time 

 in cabinets are apt to lose much of their original freshness and beauty 

 of appearance. This kind of injury chiefly affects such specimens as 

 have a bright enamelled surface, which at length becomes dull and 

 less pleasant to the touch. Several suggestions have been made with 

 reference to the probable cause of the change, which has often been 

 attributed to the efflorescence of saline matter absorbed by the shell ; 

 but, so far as I have observed, the specimens most liable to injury 

 from saline incrustation belong to genera in which the shells are 

 without enamel, as Littorina, Turritella, &c. ; and many collectors 

 are in the habit of steeping their specimens in fresh water for some 

 days, before placing them in their cabinets, — a process which is said 

 to be an effectual preservative from injury by saline efflorescence. 

 Mr. Dennison of Woolton attributed the loss of lustre in enamelled 

 shells to the ravages of a minute insect, but had not been able to 

 detect the depredator. Many of the shells in my own cabinet suffered 

 such serious injury during last winter, that I was led to investigate the 

 cause, which indeed became obvious enough by the use of a micro- 

 scope. An ordinary lens showed the enamel of the shell to be beset 

 with small bristly points ; and when a portion of the surface was 

 scraped off and submitted to a higher magnifying power, the forms 

 of at least two species of Fungi became apparent, — one resembling a 

 Mucor with a globose sporangium, the other, and much more com- 

 mon form, exhibiting both simple and moniliform filaments, with an 

 abundance of minute spores, seemingly quite free. After having been 

 carefully washed, the surface of the shell was found to be as it were 

 engraved in some places with stellular marks, in others with striae 

 forming irregular reticulations — caused, no doubt, in each instance 

 by the spreading mycelium of the Fungus. It is scarcely necessary 

 to add that attacks of this nature need not be apprehended where 

 shells are kept in a perfectly dry or well- ventilated place. A slight 

 deposition of moisture does, however, frequently occur upon their 

 surfaces whilst shells are undergoing examination, in which case it 

 would be a safe precaution to allow them for a while to remain ex- 

 posed to the air, before returning the drawer to the cabinet. — Proc. 

 Lit. and Phil. Soc. of Liverpool, No. 12, 1858. 



