HARDWICKE'S SCIENCE-GOSSIP. 



187 



other ; (3) determine its natural order in this class by 

 some such diagnosis as that given for each order by 

 Bentley ; and (4) take the individual characteristics 

 to determine the species. For example, let a mallow 

 be the unknown plant. (1) It is found to be 

 Dicotyledon ; (2) Thalamiflorae ; (3) the leaves, 

 calyx, petals, stamens, anthers, filaments, carpels, 

 and seeds, are found to answer to the diagnosis of 

 Malvaceae ; and (4) the individual of the various 

 tribes is settled. By this reductio ad unum the 

 persevering searcher hopes he has discovered and 

 named the plant aright. 2. Bentley has at the end 

 of each class an " artificial analysis of the orders in 

 each sub-class," by which perhaps the natural order 

 of a plant may be discovered, although, as it seems to 

 me, in some cases a tyro would find it somewhat 

 complicated, difficult, and uncertain. Taking the 

 mallow again as an example, one would have to 

 determine amongst all the possibilities of botanical 

 adjustment that (a) the flowers were polyandrous ; 

 (b) the leaves with stipules ; (c) carpels combined into 

 solid pistil with more than one placenta ; (</) placentas 

 in the axis ; [e) calyx with valvate aestivation ; (/) 

 stamens monadelphous ; (g) anthers one-celled ; and 

 therefore the plant belongs to the order Malvaceae. 

 3. To take in one's hand some reliable local guide, 

 e.g., De Crespigny's " London Flora," for, say, Box- 

 hill and neighbourhood, and endeavour to assign the 

 name from the list of plants stated to grow in the 

 locality. This is of course unscientific, and perhaps 

 one could not be quite certain of the result. Perhaps 

 Bentham's "Handbook of the British Flora," men- 

 tioned on page 184 of vol. xv. of Science-Gossip, 

 would afford further assistance in this method, but 

 Bentham's is a somewhat expensive work. I should 

 be glad of assistance or of reference to any work 

 which may be likely to help myself and others desirous 

 of similar information. — F. H. Hit. 



Primula veris in Scotland. — Mr. Swinten's 

 remarks on the above will surprise those Scotch 

 botanists who have more than a local knowledge. 

 P. veris is not "rare" in Scotland, being generally 

 distributed over the country, though it may be termed 

 local like many other plants ; so that it is not the fact 

 that " it is only found near Edinburgh." It is unfor- 

 tunate that Mr. Swinten has misread Sir J. Hooker, 

 and that he is unaware that the distribution of our 

 plants has been worked out to a large extent since 

 the publication of the "British Flora" in 1831. I 

 should not like to say that it is as common as in 

 England, but it certainly is very far from being 

 "rare." — A. Craig- Christy, Edinburgh. 



Physarum tussilaginis, B. and B. — I desire to 

 call the attention of the students of micro-fungi to 

 the above parasite, which is, I believe, only found 

 upon the Butter Bur (Fetasitcs vulgare). I found it 

 nearly a dozen years ago, and, not knowing it, for- 

 warded specimens to Mr. Cook, who after some time 



named it as above. Since the time referred to, I 

 have found the same fungus nearly every spring in 

 some parts of Cheshire, but never in any other county. 

 Mr. Cook reported that the plant was new in Britain. 

 I hope students will look for it in other parts of the 

 country, for as yet I am not aware of any one finding 

 the plant except myself. I shall be glad to send 

 small specimens to inquiring students ; I regret to say 

 small, but I have never found the plant in large 

 quantity. — T. Brittain, 47 Derby Street, Moss Side, 

 Manchester. 



GEOLOGY. 



Diatoms in the London Clay. — To enable 

 me to determine the exact extent of the diatomaceous 

 band in the London clay, I am anxious to obtain 

 information of any wells in progress, or in contempla- 

 tion, anywhere in the London basin, west and north 

 of London. With the help of some of your readers I 

 have no doubt that I shall shortly be able to show 

 that the zone referred to is coextensive with the 

 London clay. The details I wish for are : (1) Locality 

 of well ; (2) If begun, the depth attained. I shall 

 also be glad to hear of any railway cuttings now 

 being made in the same area. To every informant I 

 shall have much pleasure in sending a packet of these 

 mineralised diatoms, which I find from the letters 

 that reach me are attracting much attention through- 

 out Europe and America. — IV. H. Shrubsole. 



New Scotch Carboniferous Corals. — We 

 have received a copy of a paper entitled " Contribu- 

 tions to our Knowledge of the Rugose Corals, from 

 the Carboniferous Limestone of Scotland," by James 

 Thomson, F.G.S., read before the Philosophical 

 Society of Glasgow. The pamphlet is embellished 

 with most exquisite illustrations, showing the cellular 

 structure in its minutest details, and the entire work 

 bears evidence to the fact that Mr. Thomson is 

 still, what he always has been, a most indefatigable 

 worker. 



Topographical Geology. — The "Scottish 

 Naturalist " for July contains the conclusion of the 

 Rev. Dr. Milroy's interesting and valuable article on 

 the above subject, previously noticed in Science- 

 Gossip for June. Briefly summed up, the conclu- 

 sions reached are the following : In the higher 

 levels little or no change has been made in the 

 physical features, which are essentially the same to- 

 day as they were when they received their Celtic 

 descriptive names. In the lower level some changes 

 have occurred since that time — a change affecting the 

 surface merely ; waters have decreased, the courses 

 of streams have been prolonged, bog, morass, shallow 

 lake, and river-channel have become dry and firm 

 land. Such are the changes which the old names of 

 places indicate. 



