368 



NATURE 



4i 



[Fed. 20, 1890 



munication with the perforations in the teeth. Further still, a 

 special instinct leading the snake to make use of this wonderful 

 weapon of offence, and suitable nerves to i-egulate its compli- 

 cated action. 



Now, unless all these numerous variations— and they might fairly 

 be multiplied by subdivision — had in the first instance appeared 

 simultaneously in one individual, and unless all had been duly 

 connected, the whole apparatus would have been useless, and 

 there would have been nothing of which natural selection could 

 avail itself. Useful intermediate forms there can be none. A 

 rifle is a more formidable weapon than a lance or dart, but of 

 what use would be a thing half-way between the two ? The 

 venom-discharging apparatus has in it no part which could 

 possibly be dispensed with. 



To give one more instance. The tongue of the woodpecker is 

 moved forwards in a singular way ; not simply, as usual, by a 

 muscle and sinew in front of the base of the tongue, but by a 

 sinew terminating in a loop, through which passes another sinew 

 from behind the tongue which, doubling through the loop, is 

 attached to the base of the tongue. By this means, when the 

 muscle is contracted, the tongue is drawn forward with a double 

 velocity, which is to this bird specially useful. Now, it is im- 

 possible for any ingenuity to devise an action intermediate 

 between this and the usual simple pull in respect of utility or 

 complexity. But there is much more here than "a particular 

 variation." The first woodpecker that possessed this structure 

 must have had it in complete order, for otherwise the tongue 

 would not move at all. In that woodpecker it must have com- 

 menced to exist in a rudimentary form before birth, in a germ 

 possessing novel powers. 



And here I must ask, How is it that anyone questions the Duke 

 of Argyll's statement that "all organs do actually pass through 

 rudimentary stages in which actual use is impossible " ? Is it not 

 precisely this which is implied in the Darwinian statement that 

 " from the variable constitution of the ovum probably arises the 

 varying structure of the organism developed from it " ? What 

 was afterwards developed was at first rudimentary, and useless. 

 This is equally true of the whole organism — say of the serpent, 

 or of the bird — and of the entirely novel and complicated appa- 

 ratus found in them. 



To call the apparatus in either serpent or bird ' ' a particular 

 variation " would be to give up the whole case for Darwinism. 

 A wonderful combiitation of many particular variations has to 

 be accounted for ; and, so far as I can see, Darwinism utterly 

 fails to account for it. There are thousands of cases presenting 

 the same difficulty. 



There are simpler cases of specific change, in which the con- 

 currence, the simultaneous appearance, of many slight and par- 

 ticular variations is not indispensable, but only their succession 

 in due order in the course of many generations. Here, there is 

 some room for the theory. Thus perhaps, possibly, we might 

 get a giraffe. But I prefer a theoiy which, if true at all, 

 accounts as readily for the most complicated apparatus as for 

 the simplest forms oP living things. R. Courtenay. 



Hotel Faraglioni, Capri, January 31. 



Probably many readers of the recent discussion on the 

 transmission of acquired characters will regret that a moie 

 definite conclusion has not been arrived at. This is probably 

 due to the fact that the premises now in our possession do not 

 admit of a definite answer yet being given. Those who assume 

 that there is no evidence in favour of the transmission of acquired 

 characters are mostly, I presume, supporters of " the continuity 

 of the germ-plasm " theory of Weismann. Almost everyone 

 admits that individuals may and do acquire certain characters 

 due to change in environment, use, disuse, &c. ; but while many 

 maintain that these characters are transmitted to offspring, others 

 deny that such is the case, or think that the evidence is in- 

 sufficient. In supporting "the continuity of the germ-plasm" 

 theory it is impossible to suppose that the germ-plasm is con- 

 tinued from one generation to another like a portion of entailed 

 property. For each individual gives off thousands of ova or 

 spermatozoa as the. case may be, only a very few of which go to 

 produce new individuals ; therefore there is a dissipation of 

 "germ-plasm," — that is to say, in the germinal cells of mam- 

 mals of to-day there cannot be any of the identical "ger.n- 

 plasm" which existed in their remote invertebrate ancestors 

 ages ago. For all this dissipation there must be some construe, 

 live process, otherwise the germ-plasm would come to an end. 



From whence is derived this constructive material ? Clearly 

 from the exterior, for a fertilized ovum obtains material from 

 without to admit of growth and elaboration. The constructive 

 material, then, which the " germ-plasm " obtains — to admit of 

 its liberal dissemination each generation — is derived from the 

 external world, via the organism with which it is incorporated, 

 or indeed of which it forms a part. Seeing, then, that the- 

 organism — from which this germinal matter is derived — can 

 acquire characters — that is, undergo certain definite changes in 

 response to altered conditions — then it seems reasonable to 

 suppose that that part of it which ultimately finds its way to the 

 germ-cells, is also modified during its transmission, and will- 

 therefore have more or less effect upon the forthcoming genera- 

 tion. But how much variation is due to the above cause, and 

 how much to the almost infinitely various possible combinations 

 of the two unlike germinal elements, it is impossible to say. 



J. COWPER. 



Easy Lecture Experiment in Electric Resonance. 



An experiment, exhibited by me in its early stages at the 

 Royal Institution a year ago, and since shown here in various 

 forms, on the overflow of one Leyden jar by the impulses accu- 

 mulated from a similar jar discharging in its neighbourhood, is 

 so simple an illustration of electric resonance, and so easily 

 repeated by anyone, that I write todescribe it. 



Two similar Leyden jars are joined up to similar fairly large 

 loops of wire, one of the circuits having a spark-gap with knobs 

 included, the other being completely metallic, but of an adjust- 

 able length. 



The jar of this latter circuit has also a strip of tinfoil pasted 

 over its lip so as to provide an overflow path complete with the 

 exception of an air-chink, c. It is important that this overflow 

 path be practically devoid of self-induction. A jar already 

 perforated could be well utilized for the purpose. 



Then if the two circuits face each other at a reasonable distance, 

 and if the slider, s, is properly adjusted, every discharge of A 

 causes r. to overflow. A slight shift of the slider puts them out 

 of tune. 



Instead of thus adjusting by variable Felf-induction, my assist- 

 ant, Mr. Robinson, has made a slight modification by using a 

 condenser of variable capacity, consisting of two glass tubes 

 coated with tinfoil, one sliding into the other, and joined by a 

 flexible loop of wire ; an easy overflow from one coat to the 

 other being likewise provided. On making this loop face the 

 discharging circuit of an ordinary Voss machine with customary 

 small jars in situ, bright sparks at the overflow gap occur when- 

 ever the common machine sparks are taken, provided the sliding 

 condenser be adjusted to the right capacity by trial. 



There is little or no advantage in using long primary sparks ; 

 the vibrations are steadier and more definite with short ones. 

 It is needless to point out that the 2 jars constitute respectively 

 a Hertz oscillator and receiver, but fair precision of timing is 

 more needed with these large capacities than with mere spheres 

 or discs, because the radiation lasts longer and there are more 

 impulses to accumulate. Hence actual resonance as distinguished 

 from the effect of a violent solitary wave is better marked. 

 Moreover, the sparks are bright enough to be easily seen by a 

 large audience. Oliver J. Lodge. 



University College, Liverpool. 



African Monkeys in the West Indies. 



"NViTK reference to the note in Nature of February 13 (p. 

 349), on the occurrence of an Old- World monkey in Barbados,. 

 1 may point out that the same West African monkey {Cercopi- 

 thecus callitriclms) has also been introduced and is now found 

 wild in St. Kitts (cf. Sclater, P.Z.S., i866, p. 79). It likewise 



