HARDWICKE'S SCIENCE-GOSSIP. 



177 



spring, and as far as my observation of them has 

 gone hitherto, I have found this to be the case ; 

 but now I have to record an exception to this rule. 

 In a glass containing about six quarts of water, in 

 the summer of 1S72, 1 had a large number of hydras 

 (which I believe were produced from ova deposited 

 there the year before), and towards the end of the 

 summer, 1S72, they all disappeared, and the Ana- 

 chads ahinasfrum, duckweed, &c., became literally 



110. H. viridis, producing two ova. 



covered with Sienlor polT/morjihns, also a quantity of 

 3Ielicerta ringeiis, StephanoceroSy and Floscularia, 

 which died out in their turn, but while living 

 afforded great pleasure as objects for the micro- 

 scope. Then, as early as the beginning of March, 

 1S73, 1 observed a number of hydras again making 

 their appearance in the same water, and very soon, 

 to my surprise, many of them were producing sperm- 

 cells and ovi-sacs, and numbers of the ova from these 

 became attached to the sides of the glass, from 

 which many of them must have been hatched-out, 

 as, early in May, they were to be seen from the 

 smallest size and all the intermediate sizes to the 

 full-grown hydra. This unusual development may 

 be caused by their being kept continually within 

 doors, where the air has been kept at a more equal 

 temperature. 



Canterbury. " James Eullagak. 



Mole.— Goldsmith, in his "Animated Nature," 

 says the mole is not found in Ireland. Will some 

 Irish correspondent kindly inform me whether such 

 is the case ?— ?r. E. Warner, Kingston. 



ANCIENT TREES IN IRELAND. 



rfIHE attention of the readers of Science-Gossip 

 -*- has been called to the old trees in England ; it 

 may therefore interest them to get a short descrip- 

 tion of some very ancient trees in the sister isle. 



South-west of Lough Corrib, the second largest 

 sheet of fresh water in Ireland, lies a rocky plain, 

 formerly the ancient territories of Gnomore and 

 Giiobeg. This country for the most part is a 

 slightly undulating crag of carboniferous limestone, 

 while here and there patches of boulder drift, ot 

 ridges and mould of gravel, belonging to the newei 

 or second "Esker period," occur on it, and iu the 

 low places accumulations of peat. In ages long past 

 it would appear that the land was higher than 

 at present, and covered for the most pait with a 

 scrub of oak, hazel, mountain ash, holly, and tlie 

 like, with, on the drifts, larger trees, some of the 

 latter even occurring here and there in favourable 

 places all through the district. In subsequent years, 

 as the land sank, peat begau to grow in the low 

 places, till eventually large tracts of bog occupied 

 a considerable portion of the plain, while in much 

 later years the wood that remained was cut down 

 for smelting iron-ore and other purposes. Tradi- 

 tion says that the last iron-furnace in the district 

 was put out about 200 years ago, when they had 

 consumed all the wood; and this is probably correct, 

 as the last furnaces in Ireland —those of Woodford, 

 on Lough Derg, and Portroyal, on Lough Mask, 

 have been extinguished 150 years. 



When cutting the bogs, the remains of the trees 

 that formed the forest are found ; the roots and 

 blocks that occur being principally oak and yew, as 

 these trees and deal last longer in peat than any 

 others : deal sticks, however, are few here ; we may 

 therefore suppose they were scarce in this ancient 

 forest, or more probably it existed prior to the 

 " Deal-Forest age," as it is well known that in Ire- 

 land, prior to the formation of the bogs, the country 

 for the most part was covered with an oak forest, 

 while the Deal-Eorest age did not commence till 

 long after the peat began to accumulate. We are 

 not, however, at present interested in the age of 

 these different forest periods, and must return to 

 our old trees. 



The roots and trunks of the yew and oak occur 

 under the peat, following the undulations of the 

 ground ; and as the surfaces of the bogs are nearly 

 level, in some places they are found with many 

 feet of peat over them, and iu other places there are 

 only a few inches, while in one place, on the wildest 

 part of the bare crag, are the remains of some yews 

 that seem to be of a similar age to those that in 

 the low places are now covered with peat. These 

 occur in "the townlands of Corranneile-drum and 

 Kylemore (Anglice great wood), the remains of 



