Augtist 7, 1879] 



NATURE 



335 



e.g., its nature and genesis. In this way, the author ap- 

 proaches the subject of delusion, which really, in its widest 

 sense, may be said to constitute the essence of insanity ; 

 this problem is twofold : i. What is the primary mental 

 deviation ? 2. On what bodily disturbance does this de- 

 pend ? The intellectual is shown to be convertible into and 

 dependent upon emotional disturbance ; and it is well 

 demonstrated how much our state of feeling — whether 

 temporary as mood, or permanent as character — influ- 

 ences not only the imagination, but even perception. A 

 delusion may be regarded as a picture formed to suit a 

 certain frame of mind. In showing how incorrect figures 

 arise from morbid feelings, the author is less explicit ; he 

 adopts the sensationalist or association theory, but a 

 clearer notion might probably be afforded by a more 

 Platonic or idealistic theory of cognition, of which there 

 even is some suggestion once or twice. Although the 

 author adopts the emotional source of delusion as a rule, 

 yet he makes — rightly or not — exception in certain ex- 

 amples of hallucination, e.g., those arising in connection 

 with epilepsy, some toxic conditions, and in childhood — 

 which he assigns to primary derangement of the sensory 

 centres. Owing to the defective state of general patho- 

 logy, as before stated, the mode of dependence of feeling 

 on corporeal condition is far from being. satisfactory. 

 Next follow long chapters on the causation and preven 

 tion of insanity, treated first on the psychical, then on- 

 the physical, aspect ; in both, much stress is laid on 

 heredity as a factor : the former contains the most in- 

 teresting and original parts of the work. The rest of 

 the volume is of more special and technical character^ 

 being given to a tolerably full and accurate description 

 of the disease, which is regarded as fundamentally the 

 same in all cases, though wearing some variety of aspects, 

 thus affording matter for classification ; that here adopted 

 is the same as in previous editions : the description com- 

 mences with a chapter on the insanity of early life, and 

 concludes with one upon treatment, on which the author 

 holds rather sceptical opinions concerning the efficacy of 

 drugs, especially narcotics. 



In conclusion we may remark that, although the author 

 may be considered to have attained success in his chief 

 aim — the setting forth of the pathology of mind — yet no 

 more than a mere outline has been accomplished, and much 

 of this appears to have been derived from borrowed rather 

 than purely original ideas, the chief originality of the 

 author lying in their present application ; and it is to be 

 regretted that it is so lacking in thoroughness, for this 

 may suffice to prevent an otherwise highly-readable and 

 well-designed book from acquiring extensive adoption as 

 a text-book and permanence as a work of reference. 



I 



LUBBOCK'S SCIENTIFIC LECTURES 

 Scientific Lectures. By Sir John Lubbock, Bart., M.P., 

 D.C.L., LL.D., &c. (London: Macmillan and Co., 

 1879.) 



THE six lectures of which this volume consists treat of 

 the relations of insects and plants, the habits of 

 ants, and prehistoric archxology. They are well illus- 

 trated by numerous woodcuts, and are written in the clear 

 and pleasing style which characterises all Sir John 

 Lubbock's works. 



The first lecture — On Flowers and Insects — gives an 

 excellent account of some of the more interesting cases of 

 the special adaptation of flowers for insect fertilisation, 

 but contains nothing that will be new to the readers of 

 Nature. The ne.xt — On Plants and Insects — introduces 

 us to a variety of interesting and less generally known 

 relations between the insect and vegetable worlds, which 

 serve to confirm in a striking manner the general axiom, 

 that the minutest details in the structure of living things, 

 are or have been of use to them. We learn now how 

 much of what gives a special character to many plants — 

 their hairy or woolly stems, their spines, their glutinosity, 

 the hairy rings inside their flowers, their drooping habit 

 or glossy surfaces — are all of use in various ways to keep 

 off insects which would rob them of their honey or pollen 

 without effecting fertilisation. Another relation here 

 dwelt upon is that of the colouring of caterpillars in 

 accordance with the plants they feed upon, and it is par- 

 ticularly instructive as showing how impossible it is to 

 decide whether a creature is protected by its colour unless 

 it is observed in its native haunts. Few objects are more 

 beautiful, or more varied in colour and markings, than 

 the caterpillars of our different species of hawk-moths. 

 They are often adorned with the most exquisite violet, 

 blue, or white markings on a green ground, and some- 

 times also with ocellated spots of brilliant colours, yet in 

 most cases these are so arranged and balanced as to^ 

 harmonise with the general tints of the foliage and 

 flowers of the food plant and thus render the insect quite 

 inconspicuous at a little distance. In addition to the 

 excellent woodcuts of caterpillars which illustrate this 

 part of the work there is a coloured frontispiece which 

 appears to have been added as an afterthought, for not 

 only is there no reference to it in the text, but not even 

 the names of the insects are given on the plate itself. 



The next two lectures— On the Habits of Ants— give 

 an excellent summary of those interesting researches by 

 which Sir John Lubbock has added so much to our know- 

 ledge of those insects. Especially curious are the illus- 

 trations of the stupidity of some ants. One species is 

 such a confirmed slave-owner that it dies of huno-er if 

 not fed by its slaves— a fact recorded by Huber and con- 

 firmed by our modern observer. Even more striking 

 as an example of want of intellect is the experiment 

 recorded at p. 81, where some ants went round a distance 

 of ten feet to get at honey rather than jump down 

 about one-third of an inch ; and although they tried to 

 reach this small height, from a little heap of earth to the 

 glass on which the honey was placed, and could even 

 touch it with their antennse, yet they had not sense 

 enough to pile up the earth a little higher but gave it up 

 in despair and went round by the paper bridge ten feet 

 in length ! 



Numerous experiments show that some sense analogous 

 to smell, rather than vision, guides ants to their food, and 

 thus no actual power of communication from one ant to 

 anothor is needed to account for the numbers that follow 

 when one has found out a store. Some very ingenious 

 experiments prove, however, that an actual communication 

 does exist when larva; are concerned, and that one ant is 

 able to tell its fellows whether there are few or many 

 larva; to be attended to. The experiments as to the 

 effects of coloured light on ants are interesting, showing 



