HARDWICKE'S SCIENCE-GOSSIP. 



175 



flowering plants by a hundred species, and our 

 cryptogams probably'by at least 300. Already we 

 have lost several vertebrates, and a score or so of 

 flowering plants, by the cultivation of the hill-sides 

 and the draining of the bogs. But the craggy 

 summits refuse to surrender to the plough. The 

 brook-sides are still rich in mosses and hepaticse, 

 and the plantations, now half a century old, are 

 fruitful generators and protectors of life. To the 

 forest, also, we probably owe the fact that out of the 

 fourteen reptilesknownin Britain, nine or ten may be 

 counted as Leicestershire species. Into the question, 

 how it happens that only fourteen species of reptiles 

 inhabit these islands out of the existing 2,000 we 

 need not enter minutely. Our insular position and 

 our mean temperature are probably the chief causes. 

 Reptiles are a cold-blooded class, and, having no 

 warmth in their hearts, they like to feel it on their 

 skins. To bask in hot mud with a tropical sun 

 upon his back is the elysiura of a crocodile. 

 Reptiles are most numerous within the tropics, 

 and these happy islands lie 2,000 miles away from 

 that nursery of all noxious vermin. But there is 

 one thing which Leicestershire lacks. It is almost 

 a waterless county. We have brooks and we have 

 ponds ; here and there we have an artificial reser- 

 voir ; but we cannot call the Soar a river, nor 

 Groly Pool a lake, and the music of the sea is never 

 wafted to our midland ears. Many consequences 

 result from this position, and one of them is that 

 . only about 25 species of fish are native to the 

 county, while Britain numbers at least 250, and 

 the world's total is nearly 10,000. 



In vegetable life Leicestershire probably con- 

 tains about one-fortieth of the known species, that 

 is 3,000 out of a total of 120,000 ; but in that total 

 of 120,000 only the odd 20,000 are cryptogams, 

 while in our 3,000 two-thirds are cryptogams. 

 This no doubt implies that the world has not been 

 searched for cryptogams to anything like the extent 

 that Britain has been. If there really exist as 

 large a proportion of these lower forms to the 

 higher as in our county, the total will be 300,000 

 instead of 120,000, and our proportion will be one- 

 hundredth instead of one-fortieth. 



In relation to other counties, Leicestershire 

 maintains an average place in the extent of its 

 Mora. There are scarcely any data for making a 

 comparison of county cryptogamic Eloras, but of 

 flowering plants I believe no county produces 

 fewer than 700 species, nor more than 1,100, out of 

 the 1,500 British species. The Flora of Leicester- 

 shire numbers about 900, which is exactly mid- 

 way between these limits. There are no plants 

 which are found exclusively in our county, as there 

 are none which are found exclusively in Britain. 

 But we have some plants about Charnwood Forest 

 which are singularly isolated, and which the botanist, 

 when he leaves that very ancient mountain summit, 



must travel many miles to find again ; such plants 

 as the Cotyledon uinbilicus, plentiful at the Swith- 

 land slate-pits and among the slates of Wales, 

 found also in many other counties, but not in the 

 midland plain, nor probably any where within thirty 

 miles of Charnwood. Such also as Campanula 

 patula, the ornament of one only of our forest 

 lanes, and of which the next nearest station is, I 

 believe, the Malvern Hills. 



Fifty years ago we had a few relics of an alpine, 

 or sub-alpine, Flora on the Charnwood Hills. These 

 have nearly all disappeared with the progress of 

 cultivation ; but there is still a marked speciality 

 about the forest plants, which will inevitably lead 

 the thoughtful naturalist to ask, what is this little 

 rugged region, only ten miles by six ? what is its 

 geological history, that it should be the refuge of a 

 vegetable life not known in all the country round ? 



Look at it on a physical atlas, study the nature 

 and relations of its rocks, and the answer is plain. 

 It is a remnant of one of the very earliest moun- 

 tain-chains of which any traces yet remain 

 — a chain extending from the North Cape, 

 through Norway, Scotland, Westmoreland, Wales, 

 Cornwall, Brittany, and perhaps much further 

 south. The elevation of this mountain axis dates 

 back before the Carboniferous era. It has been 

 raised and lowered bodily time after time, and the 

 valleys between its peaks have been gradually filled 

 up with the vast beds of secondary and tertiary 

 rocks. But the peaks themselves are still uncovered 

 here and there, and one of these ancient peaks is 

 Charnwood Forest. 



ON THE ECONOMY OF THE FRESH-WATER 

 POLYP. 



"T HAVE previously made a few observations on 

 -*- the above subject, communicated to this jour- 

 nal in two papers : the first, published in the vol. 

 for 1872, page 132, was chiefly confined to a de- 

 scription of the sperm-cells which I had seen 

 forming on the hydra, and the ultimate discharge 

 of the spermatozoa into the water ; my second com- 

 munication was published inthe January number of 

 the present year (page 12), and also treated on the 

 same subject, but with an additional account of the 

 formation of the ovisacs on the same hydra, and of 

 their separation from the Polyp in the shape of small 

 globes, which sank to the bottom of the water. I 

 had hoped to witness the hatching-out of the young, 

 but from various causes at that time I was not suc- 

 cessful ; still I then expressed a hope that I should 

 meet with better success in future attempts, and of 

 proving in what form they leave the eg^. I had 

 expressed an opinion that they first appear as 

 minute grubs, without any tentacula. This I am 

 now, in my present and third paper, able to clear 



