52 CORRESPONDENCE. 



dom is it, that its use in such a connoctiou as that i-cfeiTed to must 

 be misleading to any reader not thorouglily acquainted witli the 

 Buhject. The "caterpillar stage " in an insect's life is that in which the 

 entire body is almost filled with a capacious stomach ; and the ci'eature — 

 endowed with a voracious appetite — eats, and eats with a greedy 

 persistence, until its skin becomes too tight for the rapidly gi-owing 

 body, and at length splits, and is cast aside — like a schoolboy's " old 

 clo " — to be replaced by a more roomy investment ! The caterpillar 

 stage, moreover, is one in which no reproJurtifc organs appear ; so that, 

 altogether, the simile is a most mifortunato one as descriptive of the 

 silent and gentle changes which are everywhere observable in the 

 vegetable world. Once more, the term " Animalcules," as quoted by 

 Mr. Lowe from Count Suminski's paper, and apjilied to these "spiral 

 thread-like bodies " is equally inappropriate. I regret very much having 

 to make the foregoing criticisms, and beg to assure the Editors, and the 

 justly well-known author of the paper referred to, that my only object in 

 doing so is to further the best interests of our new publication by 

 requesting at the outset, from future contributors, a more careful selec- 

 tion of terms used in all scientific papez-s. — Samuel H, Parkes, King'a 

 Norton. 



A Hybrid Fern. — Mr. Lowe, in his paper upon " Abnormal Ferns," 

 says that " very rarely a hybrid species may be produced " by the 

 crossing of two species ; but the examples he gives relate in each case to 

 species of the same genus. In Phanerogamous plants hybrids between 

 closely allied genera are known to exist, and wo might expect that this 

 would also be the case with Ferns. I have lately met with an instance 

 in which this hybridisation seems to have taken place. About two 

 years ago, my brother, Mr. T. B. Grove, of Eastbourne, sowed a 

 mixture of spores of Blechnum corcovadense, and Lomaria. gihha. Both 

 of the plants from which the spores were taken were well grown, with 

 stems about three feet high. Two fronds made their appearance from 

 this sowing in advance of the rest, and were carefully transplanted. 

 The other seedlings were normal, but these two, after throwing up at 

 first fronds very similar to those of. L. pihha, gialually changed their 

 character. The pinnae increased in breadth, the fronds became longer 

 and more erect, and they have now produced fei'tilo fronds intennodiato 

 between those of the two supposed parents. The diiJerences may bo 

 thus enumerated : I am of course describing average plants. L. gihha 

 has a spreadiiiy crown of 7unnerous barren fronds, the pinna; of which 

 are under half an inch broad, with a few small hhint teeth. The fertile 

 fronds, springing from the centre, are very much coiitntcted, of a light 

 green coloiir at first, covered on the under side almost completely by the 

 sori. jB. corcovadense has a much srnaller number of barren fronds, which 

 are nearly erect, and considerably longer, and have the pinnte more than 

 three-quarters of an inch broad, with a xpinulose-HOvvaio, or almost 

 dentate edge. The fertile fronds are fewer and longer still, of a pinkish 

 colour at first, quite unconlracted, the pinna; being as broad as those of a 

 barren frond, and the sori only occupying the central line. The supposed 

 hybrid has a few extei-nal fi-onds small and spreading, with narrow 

 pinna?, very like those of L. gihha, but the succeeding fronds become 

 longer and more erect, with pinna; over lialf an inch broad, and a serra- 

 tion which is intermediate between hhint and spinulose. The fertile 

 fronds are more numerous than in ]>. cnrenradense, not so long, and j-atlier 

 cnntract'ul, the piniKi; l;cing wcarcely over half the breadth of those of the 

 barren fronds, and tlie sori occupying about half of the under surface. 

 The colour of tlie yf)ung fronds also is intermediate between the pink of 

 Blechnum and the lively green of Lomaria. I have bt'foro me throe fronds 

 of about tlie same age, from plants grown under similar circumstances. 



