Junk 1, 1SGS.J 



HARDWICKE'S SCIENCE-GOSSIP. 



127 



food vacuoles and a few greyish granules could be 

 detected within the clear sarcode. Sessile on fila- 

 mentous algae, it is readily detached, and it then 

 swims freely— indeed, with great velocity— through 

 the water. It is a lively and interesting little 

 creature, and the attention of the microscopist 

 visitor to Hastings and St. Leonards is claimed for 

 it. He will doubtless have but little difficulty in 

 procuring it from either of the two localities men- 

 tioned. 



IV. Anurcea heplodon— To the description' of 

 this species, at p. 707 of Pritchard's " Infusoria," I 

 have nothing to add. In the summer of 1865 it 

 was found in some plenty in the moat surrounding 

 Southcot Manor-house, near this town. 



Three of the four species of which drawings and 

 descriptions are now presented, are, it is believed, 

 new to the British fauna. The researches of those 

 members of the Quekett Club who are more espe- 

 cially interested in the study of the Infusoria, will 

 no doubt 1 prove that they are to be found, and 

 perhaps in greater abundance, in many other 

 localities than those which are here indicated. 



MARGINAL YENATION. 



IN the number of Science-Gossip for May, your 

 correspondent, " T. W. W.," Brighton, makes 

 some comments on a paper of mine which was read 

 before the Royal Microscopical Society of London 

 in November last, and published in the Quarterly 

 Journal of Microscopical Science in January of this 

 year, on a peculiar distribution of veins belonging 

 to leaves of the natural order Umbelliferaj, and in 

 which the existence of a vein at the very edge of 

 the leaf was shown to constitute the peculiarity. 



Your correspondent takes exception to the notion 

 that this kind of venation is^confined to the Um- 

 belliferse ; but if he will take the trouble again to 

 peruse the paper, he will search in vain to find that 

 I assumed this to be the case, though I admit that 

 such an interpretation might be put on the general 

 bearing of the paper, which a different wording 

 might have prevented. 



To have given prominence to the existence of a 

 vein which I had never before seen myself, after 

 many thousands of experiments on the venation of 

 leaves, was natural ; but to have turned up the vein 

 in question in such a large number of leaves belong- 

 ing to the same order, and to have had my own 

 conclusions endorsed by some of the first botanists 

 and microscopists of the day, furnished, I conceive, 

 a still further inducement to assign to the order 

 Vmbelliferce what was its due ; and further, to with- 

 hold from other orders a character which had not 

 yet been found to exist in one even of their species, 

 much less to constitute a prevalent characteristic 

 of even a group, and still less of half an order. 



Such a conclusion was strengthened, moreover, by 

 the supposition that if a vein in such a position of 

 the leaf had been found at all largely distributed 

 amongst plants generally, it would have been 

 detected by the botanists long ere this, and some 

 notice of it would have been found in their works. 



Now that attention has been directed to the 

 existence of sucli a vein, it is not improbable 

 that it may be found in many leaves of different 

 families ; and while ] would not confine it to the 

 particular group in which I have so constantly 

 found it, still it can scarcely be expected to be dis- 

 covered in the same relative proportion of plants 

 in any other. It stands out, therefore, prominently 

 amongst the Umbelliferae, and this is all that 

 was intended to be conveyed as to conCning it to 

 this or any other order. 



Your correspondent will perhaps allow me to 

 offer one or two suggestions for his guidance, which 

 I trust he will receive for what they are worth and as 

 they are intended. It would appear to me, then, that 

 if "I. W. W." wishes to extend his observations, 

 and make them really useful, he should make him- 

 self acquainted with what has actually been done 

 in the organography of flowering plants; by so 

 doing he would familiarize himself with all the 

 varieties in the venation of leaves which have been 

 hitherto discovered and classified ; neither should 

 he rest satisfied until he has worked up the course 

 and distribution of every vein typical of each class. 

 Unless this plan be adopted — and your corre- 

 spondent's short critique on my paper shows that it 

 has not — "T.W.W." will be constantly finding some- 

 thing which has been found before, and pluming 

 himself on a discovery; or, and what is worse, 

 he may expose his inability for original observation 

 by describing inaccurately that which he is investi- 

 gating. "T. W. W" furnishes an example, indeed, 

 of this loose way of experimenting in his descrip- 

 tion of the Myrtle leaf, in which he confounds a 

 vein near with one at the margin of a leaf. The 

 Myrtle leaf, he says, "under liquor potassse gav,e 

 a marginal vein." Now this leaf, as is well known, 

 has no marginal vein at all, but is an example— and, 

 indeed, the type — of that kind of venation first 

 described by Lindley in the seventh division of his 

 classification, viz., the Pseudo-costatum, or Palsely- 

 ribbed leaf, in which the curved or external veins, 

 both or either, become confluent into a line parallel 

 with the margin, as in all Myrtaceae. So that 

 "T.W.W." has unluckily chosen a leaf typical of 

 one kind of venation in order to illustrate another 

 kind altogether distinct. It is not common to find 

 this kind of venation amongst our indigenous plants, 

 but there are some fine examples amongst the 

 exotics, as in Caladium atro-sanguineum, Caoutchouc, 

 Bupleurumfruticosum. 



Again, " T. W. W." remarks upon the separation 

 of the fibro-vascular tissue of the Myrtle leaf into 



