HARDWICKKS SCIENCE-GOSSIP. 



259 



table kingdoms. From Mr. Grenfell's description, 

 it does not seem probable that the pseudopodia 

 •could ever be used as organs of locomotion, and their 

 ■discovery does not therefore throw much light on the 

 much-debated question of the movement of diatoms. 

 It seems to me more probable that the so-called 

 " pseudopodia " are in reality identical with the 

 bristles attached to such filamentous diatoms as 

 Chsstoceros, Bacteriastrum, etc. These genera are 

 furnished with siliceous bristles distributed symmet- 

 rically round the frustules and often branched, and 

 the diagrams which Mr. Grenfell exhibited in illus- 

 tration of his paper bore a close resemblance to the 

 .figures of these "bristly" forms given in many books. 

 The principal difference seems to lie in the fact that 

 the supposed " pseudopodia" of Melosira and Cyclo- 

 tella were non-siliceous and were destroyed by boil- 

 tng in acid, whilst the bristles of the marine genera 

 mentioned above, are siliceous and indestructible by 

 heat and acids. But thi'S difference is not unnatural 

 when it is remembered that even the frustules of the 

 Melosirte were only very sparingly siliceous. It is 

 perfectly natural to expect that the greater amount 

 of silica present in the frustules of the marine forms, 

 should be accompanied by the presence of silica in 

 the processes attached to them. Whatever be the 

 ultimate conclusions arrived at with regard to the 

 nature of the supposed pseudopodia, ]Mr. Grenfell's 

 discovery is extremely interesting, and not the least 

 important feature consists in' the fact that the pro- 

 cesses, although invisible in water, were at once seen 

 when the diatoms were dried. IMicroscopists will do 

 •well to search the streams and ponds in various parts 

 of the country, and to carefully examine the various 

 species of Melosira and Cyclotella, with a view of 

 confimiing or disproving Mr. Grenfell's belief that 

 diatoms furnished with these processes are common 

 and generally distributed. 



Cleaning Slides. — In answer to the enquiry by 

 H. Verinder at page 238, I write to say that I have 

 found that by placing the " spoiled microscope slides " 

 in a strong solution of caustic potash for a day or so 

 the varnish, balsam, etc., etc., can readily be removed 

 and rendered fit for use again. I use a common 

 •earthenware receptacle for the purpose, and before 

 attempting to wash off the varnish, etc., or to clean 

 the slides I transfer them to a basin containing hot 

 water, so as to get rid of the caustic potash, other- 

 wise the fingers might suffer. — W. AT. Young. 



Cleaning Varnish. — I usually boil the slides in 

 ^,n old saucepan in water containing a small lump of 

 common washing-soda. This removes the balsam 

 .and asphalt very readily. It is advisable not to put 

 too much soda, as otherwise the solution may act on 

 the glass. For the same reason care should be taken 

 that the slips remain always immersed ; if any of the 

 liquid should dry on them, the surface will become 



permanently clouded over. When the slides have 

 boiled for about a quarter of an hour, wash in water 

 and wipe dry. — G. H. Biyan. 



New Slides. — Mr. Fred. Knock's "mounts" are 

 always microscopical gems, to be awarded the best 

 and securest place in the cabinet. The last Mr. 

 Enock has sent out is an object of this character — 

 the head of the six-eyed spider [Dysdera erylJirhia). 

 The ring of six closely set eyes gleams like a ring of 

 noble opals. From Mr. A. Flatters, of Oldham, we 

 have received another consignment of his wonderfully 

 neat botanical slides of transverse and longitudinal 

 structures. These are accompanied by neatly drawn 

 sketches, pointing out the details, so that both slides 

 and sketches ingeniously combine to render the 

 botanical student as much service as possible in the 

 shortest time. 



BOTANY. 



Flora of Kent. — To K. E. Styan's notes on the 

 local flora of Kent I have collected a few additional 

 plants, which I think will be useful to his list. In the 

 woods about Otford and Shoreham, Ccphalanthcra 

 grandijlora grows rather abundant, with Lista-a ovata 

 and Orchis maculata ; in the beech woods near 

 Shoreham, Monoti-opa hypopithys grows plentiful ; 

 on the chalky pastures about the hills, Calamintha 

 acinos, and Calamintha clinopodium, sometimes 

 in company, but le3s frequent with Nepeta cataria and 

 Campamcla glomerata ; about streams, Scivphulat'ia 

 aqiiatica and Verbena ojficinalis ; in corn-fields 

 Galeopsis ladanum and Verbascum nigrum, with 

 Ballota nigra, which grows about hedge-banks, and 

 road sides ; on the hill. Ononis arvcnsis and Cardans 

 acanlis are very common. Two butterflies which I 

 saw veiy plentiful about there was the dark green 

 fritillary, and the marbled white. — He)iry E. Griset. 



Floral Guide to Kent. — In answer to M. B. 

 Wigan (p. 238) M. II. Cowell's "Guide to East 

 Kent, etc.," was published at Faversham, and by 

 Pamplin at Wandsworth, 1839. But the only way 

 to obtain a copy now, is through the second-hand 

 booksellers. Let him try Dulau and Co., 37 Soho 

 Square, W. They had a copy in 1889, or Wheldon, 

 Great Queen Street, Lincoln's Inn. — Arthur Bennett. 



An old Experiment in preserving quickly 

 Fading Flowers. — On the evening of June 21st 

 last, I received from a friend a freshly opened speci- 

 men of the night-bloorning Cereus {Cactus grandi- 

 florus) and it still remains open, a thing of beauty, 

 with its calyx, corolla, and stamens distinct from each 

 other. As this flower invariably opens in the evening 

 and fades by the following morning, few persons ever 

 get to see it when fully opened. The method of 

 preserving it simply consists in immersing the flower 

 in water and excluding the air. I took a propagat- 



