170 



NATURE 



[yzme 23, 1887 



perhaps, that they might bite off the limbs of unwary 

 agriculturists disporting in the sea. The book should 

 have been styled the "Natural History of India," or "A 

 Manual of the Natural History of India," rather than the 

 "Agricultural Pests of India." But the fact that rather 

 too many subjects are dealt with cannot be held to 

 be a very serious fault in a compilation containing an 

 immense amount of serviceable information arranged 

 alphabetically, together with a good index, so that any 

 head can be quickly found. The author had great 

 opportunities of acquiring knowledge of the branches 

 of natural history he has here discussed while he was 

 engaged in forming the Government Central Museum at 

 Madras, and other museums in various parts of India, 

 as well as in the preparation of " The Cyclopaedia 

 of India " and his work on " The Timber Trees of 

 India." He was therefore very well qualified to 

 prepare this manual or dictionary of natural history, 

 which will serve to show Indian agriculturists what 

 are the principal foes of their crops and herds. No 

 remedies or methods of prevention are given in 

 detail. Some general instructions appear in the intro- 

 ductory chapters, such as to farm cleanly, and to use 

 certain washes and powders in case of the attack of some 

 insects. These, however, have evidently been taken from 

 lists of remedies prescribed by American and English 

 practical entomologists, and have not been actually tried 

 in India. Now that Surgeon-General Balfour has de- 

 monstrated the dangers, and indicated general remedies 

 which have been found advantageous in other climes, the 

 farmers, the foresters, and fruit-growers of India should 

 at once make experiments, and prove for themselves 

 whether these are as efficacious in the fiery heat of the 

 East as in the temperate climates of Great Britain and 

 America. 



This notice cannot be concluded without an allusion to 

 some of the errors which have been carelessly allowed to 

 remain in the book, having evidently escaped the notice 

 of the eminent scientific man who " revised nearly the 

 whole in manuscript, and the proofs as they passed 

 through the press." It is not to be expected that Surgeon- 

 General Balfour should be a skilled entomologist, but it 

 is very unfortunate for him that those on whom he relied 

 for assistance should have so signally failed him. He 

 says that the Cecidomyia tritici is the Hessian fly of 

 Europe and America. In reality the Hessian fly of 

 Europe and America is Cecidomyia destructor^ named so 

 by Say long ago, and is completely and specifically distinct 

 from Cecidomyia tritici, which is the true wheat midge of 

 Great Britain. This is a mistake which appears un- 

 pardonable in a scientific reviser. On p. 45 it is stated 

 that " the species of Necrophorus and Silpha are useful ; 

 they feed on carrion, and by scratching the ground from 

 under dead animals they partially bury them." As a fact 

 the Silpha opaca, and another species, the Silpha atrata, 

 eat and seriously injure plants of beet and mangel- 

 wurzel, as has been shown by Curtis and Miss Ormerod 

 in England, by Gudrin M^neville in France, and Taschen- 

 berg in Germany. It need hardly be said that correct 

 information as to the habits of insects is as necessary as 

 accurate nomenclature — at least to agriculturists. 



Again, under the heading Buprestida^ and Elateridae 

 (click beetles) it is remarked that the larvae feed on living 



wood, and are more or less injurious. The wire-worm, 

 the larva of Elater lineaius, is fearfully destructive to the 

 roots of crops of all kinds. In the description of Elater- 

 id^, further on, this kind of mischief is attributed to 

 their larva; ; so that there are two utterly conflicting 

 accounts of the habits of these insects, calculated to 

 puzzle the inquiring Indian farmers. 



A sweeping statement that "all the weevil family insert 

 their eggs in the stigma of the flower" cannot be sup- 

 ported, and is utterly opposed to the experience of 

 observers. A i^^n species do this, but others deposit their 

 eggs in a variety of places. Of weevils it is also said 

 that they " attack principally in their larval stage every 

 part of vegetable tissues." As a fact, many weevils do 

 incredible harm to vegetation in their perfect or weevil 

 form, and it would be difficult for the larva; — mere mag- 

 gots—to hold on to leaves. 



Sitonas, described as attacking stored grain and seed, 

 h.ive been evidently mistaken for species of Bruchi. 



These and other mistakes ought to be corrected 

 before the work is put into the hands of the agriculturists 

 of India as a text-book for their guidance. 



CELL-DIVISION IN ANIMALS. 

 La Cytodierhe chez les Animaux : Etude coniparde du 

 Noyau et du Protoplasme. Par T. B. Carnoy, Professor 

 of Biology in the University of Louvain. (Louvain : 

 A. Peeters, 1886.) 



IN this work the learned biologist of Louvain has 

 ably resumed and discussed the latest researches 

 made concerning the phenomena of cell-division in 

 arthropods and worms. It is, of course, impossible in a 

 short article to do justice to the great labour and admir- 

 able patience here displayed by the distinguished author ; 

 nor can we discuss as fully as the subject deserves the 

 several points on which Dr. Carnoy appears to differ 

 essentially from other workers in the same field, as, for 

 instance, from Prof. E. Van Beneden and from Mr. 

 Nussbaum. But the questions raised by the Louvain 

 Professor are of such importance that even a summary 

 of his present views cannot fail to be of interest. 



First, as regards cell- division in arthropods. Prof 

 Carnoy maintains that in them the direct mode of di- 

 vision may be observed in various tissues, young and 

 adult, and must be admitted to have all the characters of 

 what he terms '" un processus normal." 



This direct mode occurs either by " etranglement " or 

 by the help of a partition, just as in vegetable cells, and 

 this is verified for the protoplasm itself as well as for the 

 nucleus. 



Then, contrasting the direct with the indirect or karyo- 

 kinetic mode of cell-division, he remarks that those two 

 processes have in reality the same morphological signific- 

 ance and physiological value ; that the characters of 

 karyokinesis are inconstant, and that they may often be 

 seen passing through many intermediate stages into the 

 characters proper to the akinetic mode. Nevertheless 

 our author admits that karyokinesis is of considerat 

 importance to cell-life, inasmuch as it affords an easii 

 and surer method for making the cell dicentric ; it ali 

 leads to the division of the nuclear element into two equl 

 parts ; it enriches the protoplasm with plastine ; an| 



