HARDWICKE'S SCIENCE-GOSSIP. 



249 



obtainable. Carrot appears to be the best sup- 

 porting material ; turnips are too coarse, and 

 potatoes are full of starch grains, which are very 

 hard to get rid of. Elder pith is also, I believe, a 

 good bedding material, but 1 Lave had no personal 

 experience of it. 



To give a list of the objects most interesting for 

 section cutting would be a vast undertaking, as 

 almost every vegetable object is worth cutting, and 

 without such dissections it is impossible to obtain a 

 correct knowledge of plant anatomy. Still a few 

 may be named such as prothallia of ferns, various 

 leaves, especially glandular or hairy ones, stems, 

 stamens (anthers), ovaries, and seed-vessels of 

 flowering plants, male and female, inflorescence of 

 mosses (longitudinal sections), capsules of mosses, 

 sporangia of ferns, &c. 



Should it be desirable to keep a section for more 

 careful examination than can be done at the time, 

 remove the thin glass and the greater part of the 

 water with a fine-pointed glass tube, or a piece of 

 blotting-paper. Put a drop of pure glycerine, and 

 replace the thin glass. Glycerine has the property 

 of not drying up for a very long time, and does not 

 affect vegetable tissues to any appreciable extent. 

 Objects thus temporarily mounted in glycerine 

 should of course be kept out of the way of dust. 

 For mounting a section permanently the handiest 

 medium is that known as " Dean's Gelatine," which 

 js a stiff jelly, and is sold in small bottles Is. each. 

 Place the bottle in hot water till the jelly becomes 

 fluid, put a drop on the section, and cover with the 

 thin glass, cautiously pressing out as much of the 

 jelly as will run out. It will set in a few minutes, 

 and after a few hours the superfluous gelatine may 

 be cleaned away with a knife, and a rag moistened 

 with warm water when the mount is complete. A 

 ring or two of coloured varnish improves the ap- 

 pearance and adds to its stability. This gelatine 

 medium has two valuable qualities, viz., that being 

 almost of the same density as sap and water, it does 

 not alter the tissues mounted in it ; and also, that it 

 preserves the colour of the chlorophyll remarkably 

 well. 



In cutting sections in carrot or similar material, 

 always see that the razor is well wetted, as it makes 

 ir, cut much more easily, but it is better dry if pith 

 be used. To explain the structures seen in the 

 various sections no book is better than Sach's, 

 which can be obtained in most good libraries, in 

 either German, Prench, or English, the last French 

 edition being perhaps the best. 



Cutting sections of animal tissues I have wholly 

 passed over, as so many involve hardening and pre- 

 parations in various ways, that few but medical 

 students who have recourse to a suitable laboratory 

 are likely to pay much attention to this branch, 

 albeit a most interesting and important one. 



Greenwood Pim. 



THE ORIGIN OE THE PLANT NAMES 

 OF THE WARREN* 



WE pass on now to the Cruciferae or Cruciform 

 order, named on account of the petals being 

 in the shape of a cross. Of this order there have 

 been found in the Warren, Thlaspi arvense, Capsella 

 Bursa-pastoris, Cardamine pratensis, Nasturtium 

 sylvestre, and Sisymbrium officinale. Thlaspi 

 arvense (Field Penny Cress) is a mixture of Latin 

 and Greek, thlaspi coming from the Greek verb 

 thlao, to crush or to bruise, and arvense from the 

 Latin arvum, a field. The plant was so named be- 

 cause the seed was bruised and used like mustard. 

 Others say that the word is derived from the Greek 

 verb thlao to flatten, and that Pliny mentions that 

 the whole genus was named on account of the large 

 flat seed-vessels ; but the Greek word means to 

 crush or bruise, although the idea of flattening may 

 be implied in that of crushing. The name Cress is 

 probably connected with the Latin cresco, to in- 

 crease, and is used of this and similar plants which 

 grow or increase rapidly. Penny Cress derives its 

 name from the large flat seed-vessels around the 

 upper part of its stem, which are about the size of 

 silver pennies. Capsella Bursa-pastoris (common 

 Shepherd's Purse)derives its name from the shape of 

 its flat seed-pouch, which resembles a rustic purse. 

 Capsella is a diminutive of capsa acase. Cardamine 

 pratensis (Cuckoo Flower) is a mixture of Greek 

 and Latin. Cardamine, according to Miss Pratt, is 

 compounded of kardia, the heart, and damao, to 

 fortify ; which is altogether wrong, for the word 

 damao does not mean to fortify, but to tame, to sub- 

 due, to overcome ; nor can I think that the word 

 has any connection whatever with kardia, the heart. 

 There are three words in Greek, kardamon, karda- 

 mis, kardamine. Mr. Johnstone, with whom I have 

 corresponded about this word, says that Cardamine 

 is one of this triplet, the first, kardamon, being now 

 taken as representing nasturtium, and the other 

 two forms applying to some kindred genus of Cruci- 

 ferae or Cress worts, possibly Lepidium. Pratensis, 

 is from the Latin prat urn, a meadow. One common 

 name of this plant is Cuckoo Flower. It is thus 

 explained by Gerarde : — " It doth flower in April 

 and Maie, when the cuckoo doth begin to sing her 

 pleasant notes without stammering." Another 

 common name is Lady's Smock, " given," says Dr. 

 Prior, "on account of the resemblance of its white 

 flowers to little smocks hung out to dry, as they 

 used to be once a year, at that season especially." 

 The next plant, Nasturtium, has an amusing etymo- 

 logy, viz., nasus tortus, a distorted nose, on account 

 of the pungent properties of the plant, which pro- 

 duce violent sneezing, and therefore a temporary 

 distortion of the nose. Sylvestre means woody, 

 from the Latin sylva, a wood, a forest. Sisymbrium 



* Continued from p. 131. 



