April 6, 1882] 
NATURE 
929 
am anxious to state it, in order to clear myself of any suspicion 
of having borrowed from that distinguished writer without 
acknowledgment. W. OGLE 
April 2 
Rime Cloud observed in a Balloon 
In his letter, inserted in NATURE, vol. xxv. p. 507, Dr. Her- 
mann Kopp says that ‘‘when Kratzenstein (1744) advocated 
the opinion anticipated by Halley (1686), that water-vapour may 
be condensed in a vesicular state, he availed himself of the 
observation that in clouds and mists and condensed steam over 
boiling water, a rainbow is not to be observed in reflected light.” 1 
have good grounds to suppose these negative observations were 
made only because the intensity of reflected light was not suff- 
cient, as a white rainbow is produced under these circumstances. 
In support of these assumptions, I may he allowed to quote an 
observation published by M. Faye in vol. xxviii. of the Comfres 
rendus, 1849, p. 244, where the celebrated astronomer says :— 
“J'ai observe cette nuit un phénomeéne que je signale aux 
personnes qui l’occupent d’optique méteorologique. En sortant 
Wune salle de travail qui donne sur le pare de l’observatoire, j’ai 
remarque que la lumiére d’un bec de gaz en arriére produisait en 
face de moi par la porte entrouverte un are-en-ciel blanc semblable 
aun halo lunaire . . . Cet arc-en-ciel blanc doit étre aisement 
réproduit par les temps de brouillards; ou pourrait le faire 
naitre a la lumiére électrique . . . et ’étudier plus complete- 
ment que je ne I’ai fait.” 
It is to be regretted that the suggestion of the illustrious 
astronomer has not been taken into account by the physicists in 
an age when the electric light is so frequently in their hands, I 
believe that this kind of experimentation will elucidate the con- 
troversy, and afford some new ideas on the constitution of clouds 
under several circumstances, as artificial clouds may be produced 
by using jets of steam or condensing steam over a boiler. I 
believe a white rainbow, which is really the corona of the aéro- 
nauts, would appear under these circumstances, and the pheno- 
menon would take another aspect when electric light falls on solid 
snow. ‘The electric lighthouses now building will afford to the 
keepers many opportunities of making this observatien. I take 
advantage of this opportunity to ask M. Hermann Kopp if he 
will obligingly suggest some observations to be made in a bal- 
loon for examining whether the minute particles of water are 
liquid or solid. By doing so, he will confer a great benefit on 
aéronauts next winter. W. DE FONVIELLE 
The Kunnungs 
HAVING just returned from an exploring expedition east of 
Asam, where I met a number of ‘‘ Kunnungs,” I may report 
that they appear distinct, both in language and physique, to the 
Naga groups south of Asam, and, in language, have affinities 
with Singphos. Those 1 saw, were with one exception, much 
more prepossessing in appearance than the other hill-savages, 
and in colour very pale, z.e. 33 and 45 of Broca’s scale. I have 
got a limited vocabulary. They are great iron and steel workers, 
and extend from the Mli-kha to what they call the boundary of 
China, living on pile platform dwellings, raiding like all the 
hill-men about, having ‘‘morongs,” or separate houses for 
the unmarried ; like others, also, their ‘‘ morals ” (as we should 
say) begin with marriage. 
I am now preparing some notes of my trip, and send this as I 
am writing, as it may interest some to know whom these people 
seem like, S. E. PEAL 
Subsagar, Asam 
Burrowing Larve 
IN his letter anv¢e p. 265, Dr. Hagen states that he had ‘‘ been 
informed by M. Lesquereux that a large number of magnolia 
leaves, from the Tertiary of Alaska, show serpentine trails not 
larger than a thread, running all over the leaves, apparently under 
the epithelium,” and Dr. Hagen evidently believes them to be 
the mines or burrows of some Tineid larve. Precisely such 
mines are now made in this country, in the leaves of magnolias, 
by a larva of the genus Phyllocnistis, Zell. The moth has not 
been bred from the larvz, but the mine and larve are indis- 
tinguishable from those made by Phyllocnistis liriodendronella, 
Clem., in leaves of Lirtodendron tulipifera, and doubtless it is 
the same species in both of these allied trees. ‘‘ What is a 
species?” however, is a doubtful question in Phy Zlocnistis, at 
least in our American species. No species of this or any other 
genus is known to burrow in the leaves of any of the other genera 
of plants named in Dr. Hagen’s letter besides Magnolia, 
Liquidambar, and Sassifras. Another PAy/locnist’s mines the 
leaves of Liquidambar, and has been described by me under the 
name of P. liguidambar-isella, but it is probably identical with 
P. vitifoliella, Cham. The mine is similar to, but distinct from, 
that of P. Liriedendronella. The larva which mines Sassafras 
leaves is that of Gracilaria sassafracella, Cham., but it leaves 
the mine at a very early stage of larval life, when the mine is too 
small to be recognised in a fossil leaf, unless it has been 
unusually well preserved. In this connection I wili add that I 
distinctly remember having somewhere seen a figure, by Les- 
quereux I think, of a fossil leaf of a species of Ace, on which 
there were several blotches, one of which bore a strong resem- 
blance to the mine of Zithocolletis aceriella, now made in leaves of 
Acer saccharinum ; but as I saw only the figure, and not the 
fossil, I cannot be certain that it was a mine of that larva. 
Covington, Ky., U.S.A., March 10 V. T. CHAMBERS 
Vignettes from Nature 
WILL Dr, W. B. Carpenter kindly tell us where in ‘South 
America” are the ‘‘coprolite diggings” from which he had 
“Just seen a collection of sharks’ teeth”? Iam aware that at 
Bull River, South Carolina, North America, are vast deposits of 
“coprolites” (almost identical in character with those of our 
Suffolk Cray), which are largely imported into England from the 
United States. Of these Bull River sharks’ teeth, &c., I have 
had many specimens. W. BUDDEN 
Ipswich, March 23 
Red Flints in the Chalk 
AT one part of Caterham Valley, Surrey, there is an 
example of an abundance of red flints similar to that men- 
tioned by W. Fream (NATURE, vol. xxv. p. 437). The colour is, 
doubtless, due to the presence of oxide of iron, but I have not 
tested it, I find that the red flints invariably contain the remains 
of sponges, the network of spiculz of which, leing coated with 
the oxide of iron, show up in crimson or orange on a ground of 
black flint, and are very beautiful objects under a lens. Thus it 
appears to me that the redness observable in these flints is mostly 
due to the inclosure of sponges which contain either oxide of 
iron or iron which afterwards became oxidised. The yellow 
oxide of iron is disseminated throughout the chalk itself, some 
strata being very much stained by it. | JOHN BApDcock, Jun. 
270, Victoria Park Road, E. 
ON THE DISPERSAL OF FRESHWATER 
BIVALVES 
HE wide distribution of the same species, and of 
closely-allied species of freshwater shells must have 
surprised every one who has attended to this subject. A 
naturalist, when he collects for the first time freshwater 
animals in a distant region, is astonished at their general 
similarity to those of his native European home, in com- 
parison with the surrounding terrestrial animals and 
plants. Hence I was led to publish in NATURE (vol. xviii. 
p- 120) a letter tome from Mr. A. H. Gray, of Danvyers- 
port, Massachusetts, in which he gives a drawing of a 
living shell of Unio complanatus, attached to the tip of 
the middle toe of a duck (Querguediula discors) shot on 
the wing. The toe had been pinched so hard by the shell’ 
that it was indented and abraded. If the bird had not 
been killed, it would have alighted on some pool, and the 
Unio would no doubt sooner or later have relaxed its hoid 
and dropped off. It is not likely that such cases should 
often be observed, for a bird when shot would generally 
fall on the ground so heavily that an attached shell would 
be shaken off and overlooked. 
I am now able to add, through the kindness of Mr. W. 
D. Crick, of Northampton, another and different case. 
On February 18 of the present year, he caught a female 
Dytiscus marginalis, with a shell of Cyclas cornea cling- 
ing to the tarsus of its middle leg. The shell was “45 of 
an inch from end toend, *3 in depth, and weighed (as Mr. 
Crick informs me) *39 grams, or 6 grains. The valves 
