July 12, 1894J 



NA TURE 



243 



groups of animals a distribution of forms exists, such 

 that the higher are found nearer the centre of the great 

 land masses that radiate from the North Pole ; the lower 

 towards the ends of continents and the islands reaching 

 down into the watery waste of the southern hemisphere. 

 This sequence of form he now explains by an interesting 

 view. The natural selection of individuals does not de- 

 pend upon their protective or adaptive qualities, but upon 

 their good or bad constitutions. If an insect-eating bird 

 gets upon the track of a set of caterpillars, it is unlikely 

 to distinguish between the slight variations they may 

 have in protective colouration. But in the struggle be- 

 tween race and race, the race better protected will, on 

 the whole, attract the attention of enemies a less number 

 of times. The selection between individuals is a selec- 

 tion between the generally strong and the generally weak, 

 between those whose life-pulse beats high and those 

 of low vitality ; not between those with an organ or 

 an adaptation a shade weaker or stronger. The ap- 

 pearance of the dift'erences between races which tend to 

 the adaptation of some and the non-adaptation of others 

 are due to causes independent of selection. Thus it 

 happens that in cases where there is a wide range there 

 are more varied local conditions, more local races, and a 

 greater material for that competition between races which 

 is the cause of progress. And thus where continents 

 spread widely evolution is more rapid than in the con- 

 fined areas which stretch towards the South Pole. This 

 view is complicated by the further view that the result of 

 crossing is not a production of variation by the mingling 

 of characters, but an equalisation of the divergent 

 characters of individuals. 



Those who are interested in controversy will find these 

 and a number of most interesting views and collections 

 of facts in Dr. Haacke's book. But they are so entangled 

 with elaborate and chiefly mathematical arguments 

 against the views of Weismann, that they form some- 

 what difficult reading for the uncontroversially disposed. 

 Moreover, they are complicated by a highly elaborate 

 theory of Dr. Haacke's own invention. He accepts the 

 view of Verworn that the nucleus is an organ of meta- 

 bolism for the cell, and sees in the plasma with the centro- 

 some as its organic centre, the true bearer of heredity. 

 The plasma is composed of ultimate elements called 

 "gemma;." These are rhombic prisms, the ultimate 

 shape of which is as proper to protoplasm as are the 

 shapes of inorganic crystals to their chemical composi- 

 tions. These "gemmae" are built up into "gemmaria" 

 by association into variously shaped layers and rods. 

 The shape of the "gemmaria " determines the shape of 

 the whole organism, and a number of ingenious refer- 

 ences of symmetry to hypothetical gemmarial structures 

 are given. The "gemmaria' of a whole organism are 

 identical, and by a system of attractions and repulsions 

 remain in a condition of equilibrium. But outer forces 

 acting upon any part of the organism disturb this system 

 of equilibrium until the organism settles down into a new 

 position of equilibrium. As the germ cells contain 

 gemmaria like all the gemmaria of the body, outer 

 changes cause a new condition of equilibrium in them, 

 and this new condition naturally is the starting-point of 

 the new organism. The differences between individuals 

 are chiefly differences between the degrees of closeness 



NO. I 2S9, VOL 50] 



in which the gemma? of " gemmaria "are attached to each 

 other. Those with weak attachment have weak constitu- 

 tions, and in each generation are weeded out. In sexual 

 union, the primary cause of which is the attraction 

 between similar crystalline systems, the inequalities of 

 attachment between the gemma; are redressed. 



It is perhaps unnecessary to add that Dr. Haacke 

 considers that acquired characters are inherited, but that 

 it is absurd to expect any proof of this inheritance, as, 

 he says, the whole organic world is a proof of it, and 

 because without it epigenesis would be impossible. 



P. C. M. 



AGRICULTURAL ENTOMOLOGY. 



Handbook of the Destructive Insects of Victoria. (Pre- 

 pared by order of the Victorian Department of Agri . 

 culture.) By C. French, F.L.S., Government Ento- 

 mologist. Part II. (Melbourne : 1S93.) 

 TWENTY notorious insect pests are dealt with in 

 this volume, each being illustrated by a coloured 

 plate, which shows not only the metamorphoses of the 

 insect, but the nature of the mischief of which it is the 

 cause. The chapter on each insect is complete in itself, 

 and there is no definite order of treatment of subjects ; 

 nor in a volume of this character was any such sequence 

 called for. Arranging the insects systematically, how- 

 ever, it is found that the Homoptera are represented by 

 the green peach aphis, the black peach aphis, the orange 

 aphis, the grape louse, the cabbage aphis, the cottony- 

 cushion scale, the oleander scale, the lemon scale, and 

 the red scale of the orange ; the Coleoptera by the plum 

 curculio, the cherry green beetle, the apple root-borer, 

 and the strawberry beetle ; the Lepidopteraby the orange 

 moth, the case-moth of the orange, the vine moth, the 

 silver-striped vine moth, the potato moth, and the cab- 

 bage moth ; and the Neuroptera by the so-called " white 

 ant," Termes australis, Hagen. With three or four ex- 

 ceptions, therefore, most of the insects dealt with are 

 pests of fruit trees, and not more than half a dozen of 

 them have acquired notoriety in England. 



.As the main object of the work is to supply to growers 

 information as to the means whereby they may protect 

 their crops against the ravages of injurious insects, we 

 naturally look for very full information under this head, 

 and it must be admitted that the author has admirably 

 acquitted himself in this respect. In addition to the 

 concise details of methods of prevention and of remedy 

 given under the head of each pest, there is a well-illus- 

 trated appendix, containing descriptions of the various 

 kinds of apparatus which are coming more and more 

 into use for insecticidal purposes. Several appreciative 

 references are made to the ingenious English-made 

 spraying machine known as the " Strawsonizer " ; but 

 the light knapsack modifications of this apparatus, 

 termed the " Antipest " and " Notus " respectively, are of 

 too recent introduction to find a place in the volume. The 

 list of insecticide materials given in the first volume of 

 the work is supplemented here by a further series. More- 

 over, as part i. contained a list of the insectivorous birds 

 of Victoria, so part ii. contains a list of the fruit and grain 

 eating birds of the colony. We are glad, also, to note 



