42 



HARDW1CKKS SCIENCE-GOSSIP. 



are entirely new to Ireland. They were collected by 

 Mr. G. Croasdaile. — Joseph W. Williams. 



Variation in the Mollusca. — A few words 

 only in reply to Mr. Cockerell's remarks on the first 

 part of my papers/under this heading, which were 

 published on pp. 211-213, ante. The majority of 

 his strictures have been, I think, sufficiently answered 

 in Part II., published in the August number. A word 

 or two as to my impressions of the meanings of the 

 words "species," "variety" and "form." The 

 definition of the word "species" is to me a class of 

 individuals each of which can be considered to be the 

 descendant of the same protoplast or of the same 

 pair of protoplasts; a "variety" as a class of 

 individuals, each of which belongs to the same species, 

 but each differing from other individuals of the 

 species in the points wherein they agree amongst one 

 another. The word " form " to me has practically 

 the same meaning as "variety"; theoretically, a 

 " form," however, may be considered as less constant 

 than a " variety," and occurring more spasmodically. 

 What may be considered a "form"' on Hampstead 

 Heath may be considered a "variety " in Worcester- 

 shire. My impression of the meaning of the word 

 "form" will be seen not quite to accord with that 

 expressed by Mr. Cockerell, who thinks them " a 

 grade less distinct than varieties proper, as varieties 

 are than sub-species and sub-species than species" 

 — a definition working on which it is no wonder that 

 he has never been able to satisfy himself about the 

 line to be drawn between " varieties" and "forms." 

 With regard to the various illustrations drawn of the 

 tree, names of people, names of chemical compounds, 

 etc., I say little, for when they are looked into and 

 thoroughly examined they hate none but a very 

 superficial relation to the matter of variety-names. 

 But Mr. Cockerell adds, " The common language has 

 grown to suit the popular mind, and is too illogical 

 and loose in its application for scientific names." It 

 will be noticed by the reader that I said nothing 

 about the common language of the popular mind, but 

 of the exact colour-terms of the English language ; 

 white is white, red is red in that language and 

 nothing else. And what shall we say to some of our 

 Latinised variety-names ? Planorbis umbilicatus 

 (compla/iatus) var. albina is described as white or 

 colourless ; P. contortus var. albida as nearly white ; 

 IT. hortensis var. albina as whitish or white ; 

 H. cantiana var. alba as entirely opaque white ; 

 H. hispida var. albida as white or colourless ; and so 

 on. What I say is, that it is better for the sake of 

 exactness to describe a variety simply as white, 

 opaque white, whitish, colourless, or whatever it may 

 be; then these so-called "scientific names" will 

 not be "illogical and loose." Linne's fragilis is, I 

 believe, generally known to English workers by 

 Jeffreys' description : " shell much smaller, narrower, 

 thinner, amber-coloured" — whether it be the exact 



thing which Linne meant when he described Helix 

 fragilis in his " Systema Naturae," I will not decide, 

 and does not matter much to me ; but what does 

 matter is that Jeffreys' description is what is meant 

 when the word fragilis is used by the great majority 

 of present-day conchologists. The translated descrip- 

 tion of Moquin's var. ptwiila is " shell much smaller, 

 amber-coloured." I understand Locard's var. fulva 

 of B. tentaadata as a " tawny " and a " shiny " one ; 

 and if this be so, I do not see much difference (not 

 enough at any rate to warrant a Latinised name did I 

 believe in naming " unicolorous colour-changes") 

 from the typical yellowish, horn-coloured and glossy 

 type. I give a large discount to aterrima of A. atcr 

 for the same reason. I neither see anything between 

 vars. fragilis and ptimila of L. stagnalis ; the descrip- 

 tive difference is that fragilis is narrower and thinner 

 /than the type), while these two attributes are not 

 given by Moquin to his piimila, but primd facie 

 (because it is described as "much smaller " than the 

 type) they are not to be denied it. I do not see why 

 Mr. Cockerell should demur to my retaining Limneea 

 peregra var. ovata, even if he may "be an old fellow, 

 fat with rest and good living," which I am not as 

 prepared to admit. It is a good structural modifica- 

 tion of the type-shell. The fact that " Hazay says 

 typical peregra can be produced from ovata by 

 transplanting the eggs of the latter to water which 

 contains much carbonic acid," I consider as proving 

 very little indeed. I should expect some of the eggs 

 of ovata to resolve into typical peregra if transplanted 

 into any water or even if kept in the water of its own 

 pool ; I think every biologist would expect the same, 

 for they would but be " reversions to ancestral 

 conditions." Indeed, if no resolution occurred, I 

 should begin to think it a distinct species and not a 

 variety at all. I should expect the same of any 

 variety. In conclusion, it appears from the com- 

 mencement of Mr. Cockerell's note that in his 

 opinion it is the best thing, whichever way you take, 

 to have " the whole hog or none ; " but personally 1 

 am of the opinion that it is well in this matter, as in 

 others, to steer a middle course. I condemn not all 

 things in the council of the variety-mongers, nor do 

 I approve all things in the synod of those who go the 

 polar opposite to variety-naming in its totality. — 

 7. IV. Williams. 



N.B. — In Part III. p. 203, second column, line 

 two from top, the word "foundation " should be 

 "fecundation." On line sixteen the comma should 

 be deleted between Sedgwick and Minot. — J. IV. IV. 



Additional Worcestershire Birds. — Hen 

 harrier, Circus cyancus, L., Alcester ; red-breasted 

 merganser, Mergus scrraior, L., Clifton-on-Terne ; 

 kittiwake, Rissa tridactyla, L., Spetchley. — F. G. S. 



Metamorphoses of the May Fly :— Mr. 

 Swinton, who wrote in the December number of the 

 " Metamorphoses of the May Fly," seems to have 



