Oct. 1 8, 1883] 



NATURE 



589 



"Zoology at the Fisheries Exhibition" 



In your issue of the 20ih ult. (p. 489) a direct challenge is 

 made upon several points as to the veracity of my former letter. 

 ' ' The Writer of the Article " states what he terms certain 

 "facts," — the first being that I informed the jury of Class V. 

 that certain corals under my name, 813 b, were in the case with 

 Lady Brasse>'s corals, and for ned part of that collection. I beg 

 entirely to deny this What I stated to one of the members of 

 the jury in answer to his allusion to my exhibit was, that owing to 

 uiy being so busy I was unable to exhibit my own corals, and thai 

 all my energies had been thrown into the arrangement of Lady 

 Brassey's ca-e. Whoever informed "The Writer of the Article" 

 must have greatly misunderstood my statement. The second 

 " fact " with regard to the opinion of experts I think I need not 

 answer. Opinions may differ. With regard to "fact" three, that 

 neither the series of corals in the British Museum nor those of 

 the Challenger Expedition have been accessible for purposes of 

 examination for some considerable time. It uill be sufficient to 

 say that my description and figures of Lady Brassey's corals 

 were published in the Annth and Magazine of Natural History, 

 vol. ix. No. 50, in February, 1SS2, some time after the publica- 

 tion of the volume of the Challenger Reports containing Mr. 

 Moseley's monograph of the " Hydrocorallinidae," and a con- 

 siderable time after the specimens themselves were exhibited to public 

 view in the galleries of the British Museum. Those specimens, 

 together with the other corals of the general collection of the 

 British Museum have only been withdrawn from public view 

 within the last few months. Bryce- Wright 



Organic Evolution and the Fundamental Assumptions 

 of Natural Philosophy 



By the principle of heredity we understand a tendency in 

 an organism to reproduce in successive order the variations 

 which appeared in its ancestors, the leaning being on the « hole 

 to fixity of direction : by the principle of variation the tendency 

 of an offspring to vary in a degree more or less from its parents. 

 Included in heredity, I suppo-e, are the tendencies tn vary, as 

 well as the actual succe-sion of changes in the life-history of the 

 ance tors of the organism : those tendencies to vary being con- 

 ceived of as series of which some terms may modify or counter- 

 act others. If I am right in this description, it appears to me 

 that heredity is an example of inertia acted on by a principle 

 analogous to the first law of motion, and very closely allied with 

 it, if indeed it is not the case that the laws of motion are special 

 cases of wider principles or laws. Following the same line of 

 thought, " variation " may be explained as action analogous to 

 that of forces on a body drawing it from its straight line of 

 motion or its rest. The forces (if I may use that term) which 

 thus cause variations in any particular organism would be : — 



(1) The resultant of difference of conditions cooperating with 



(2) The resultant of inherited tendencies. 



Again, answering to the second law of motion, we may per- 

 haps assume that degree of variation is proportional to the forces 

 acting, namely, proportional to the intensities of (1) and (2) 

 above and to the correspondence or divergence of direction in 

 which they tend. If the above hypotheses are accurate, we 

 have, 1 think, an explanation of the possibility of protozoa, &c, 

 remaining practically unchanged during great changes of condi- 

 tions. For those genera which show a tendency to great varia- 

 tion in the individuals at the same time seem to present no fixed 

 line of tendency. The result of heredity (as defined above) in 

 these cases is not definite variation tending in certain fixed 

 directions, but great individual or indefinite variability. And 

 their phenomena of reproduction I think account in soaie degree 

 for this. 



On the same hypothesis we may explain, among-t other 

 things, tne plasticity of organisation of cultivated plants. One 

 of the conclusions also that would follow would be that "rever- 

 sion" would not happen except as a reultant of the tendencies in 

 fixed directions having nullified each other, or having converged 

 in the direction of rever.-ion. 



To carry the analogy further. Answering to the third law of 

 motion, that action and reaction are equal and opposite, we may 

 perhaps assume that alteration of some organs or properties in 

 the organism, wrought by change of conditions together with 

 heredity, brings about that modification of other properties or 

 organs which Darwin spoke of under the name of "correlation." 



I should feel indebted to any one who would point out any 



mistake that I have made in this, or would show if the assump- 

 tions I have made are untenable. Frederick W. Racg 

 Masworth Vicarage, Tring, September 25 



Curious Habit of a Brazilian Moth 

 Mr. E. Dukinfield Jones (Nature, May 17, p. 55) 

 may be interested to learn that the habit of Panthera apardalaria, 

 which he describes, of sucking up water and discharging it 

 simultaneously ah ano, is not confined to the moth noted by 

 him, but is common to several other lepidopterous insects. 



I have watched several species of Callidryas and Fieri s both 

 in Ceylon and Brazil, doing the sime thing; also Pafilio Eri- 

 ihonius, Cram, in the latter place, and its ally, P. Demoleus, L., 

 at the Cape of Good Hope. I have seen the "white butter- 

 flies" in thousands, settling on the mud and damp places in the 

 jungle paths in all these countries with their trunks thrust into 

 the soil, drawing up copious supplies of water as if they were so 

 many miniature Abyssinian pumps ! The drops ejected were by 

 no means "minute," were rather very large, and I should say 

 6o would much overtop the marks in a minim measure glass, or, 

 roughly speaking, more than fill an ordinary teaspoon, said to 

 equal sixty drops. I have somewhere (I forget where), among 

 my fugitive writings, noted this fact : stay, I noted it once at 

 least in the Field in 1S73, February 7. A large moth (Catoeala ?), 

 a fine "yellow underwin '," vi-its the toddy vessels in Ceylon, 

 and gets very drunk, not having joined the "blue ribbon" army, 

 nor having the fear of Sir Wilfrid Lawson before his eyes ! 

 I suspect this fellow finds the liquor too good to eject so rapidly, 

 but I have seen small moths of various kinds drinking ordinary 

 sap, and ejecting it like the before-named butterflies. 



British Consulate, Noumea, July 24 I ■'. L. Layard 



Meteors 



During the month of August I watched the meteors from 

 Logiealmond parish manse, Perthshire, but there the weather 

 was most unpropitious for observing any celestial phenomena, 

 so only a few were seen; whereas therein August last year 1 wit- 

 nes-ed some gorgeous showers of brilliant meteors, which the 

 readers of Nature may recollect. Here in Paisley, on the la t 

 Sunday of August, about 1 1. 50, a very large meteor blazed 

 from due south to due east, with a long train, lasting for a 

 minute, and keeping parallel to the horizon, nearly midway to 

 the zenith. The month of September was unusually rich in 

 meteors, but they were generally small and transient, and 

 seemed to be very remote, some of them dashing straight up. 

 A bright but momentary one shot up at right angles from the 

 Pleiades. On September 24, at 10.55 P-m., a very peculiar 

 meteor started fr >m Aldebaran, and exploded in the head of 

 Pisces, under the Square of Pegasus. It was dimly seen through 

 a haze, with a long streak behind, giving unmistakable evidence 

 of its large size ; yet, though scarcely seen above its path, 

 brightly shone the Pleiades, Aries, and the Square of Pegasus. 

 On the 25th, at 1 1 . 56, a similar one, scarcely seen, sailed 

 through a haze from Pisces to Altair, exhibiting a long trail of 

 broad light, showing that it was a large one. September 30, at 

 0.12, a meteor considerably larger and brighter than Jupiter 

 passed from the third bright star in Auriga (taking Capella as 

 the first), and exploded close to the lower Pointer in the Plough, 

 leaving a long train of reddish light behind it. On the night of 

 the 29th and morning of the 30th, up to 4, the meteors were 

 unusually large and of longer duration, and altogether more 

 numerous than I have ever seen them in September. A few 

 momentary meteors were seen on the night of September 30 

 and morning of October 1 Donald Cameron 



Mossvale, Pai-Iey, October 1 



The Uselessness of Vivisection 

 You will probably permit me to point out that it would be 

 only reasonable for Mr. George J. Romanes to possess a little 

 information on the subject he is dealing with before he accuses 

 another of being "in a quagmire of ignorance and inaccuracy." 

 The pamphlet against which he levels his abuse does not deal 

 with physiology, but with surgical questions. My efforts have 

 not been directed so much against vivisection as against the 

 mendacious statements which have been made concerning 

 advances in surgery alleged to be due to its practice. These 

 have been used to hoodwink the legislature and blindfold 



