i8* 



NATURE 



[Nov. 6, 1879 



small branches of live-oak into one of the mounds de- 

 scribed, near the " gates." These were soon withdrawn, 

 and seen to be covered with " cutters " busily occupied. 

 It was thus possible to examine them at work by the light 

 of a lantern, as it will doubtless be remembered that night 

 is the busiest time with these active ants, supplying their 

 minuteness with a most effective shelter. 



The " cutter," usually an ant belonging to the caste 

 next below the " soldier " in size, first grasps the leaf with 

 outspread feet, and begins to cut into its edge by a 

 scissors-like action of her sickle-shaped toothed man- 

 dibles. Thus she naturally proceeds, with steady motion, 

 until the mandibles have clipped off a portion of the leaf, 

 having a circular edge, clean cut. The feet turn as the 

 head turns. The cutter sometimes drops, with the piece 

 just cut, to the ground ; but probably, if possible, retires 

 when the piece has dropped, to continue her professional 

 occupation. Mr. McCook found at the foot of one tree a 

 pile of cut leaves, to which clippings were continually 

 being added, dropped by the cutters. The carrier at the 

 foot took them up and carried them to the nest. The 

 loading of the cuttings is thus accomplished : the piece 

 is seized by the curved mandibles, the head is raised, the 

 piece is thrown back by a quick motion, seeming to be 

 lodged on its edge within the deep furrow that runs along 

 the entire median line of the head with the exception of 

 the clypeus, and supported between prominent spines on 

 the edge of this furrow and on the prothorax. 



The young saplings near the mound at Camp Wright 

 were found almost entirely stripped of leaves by these 

 ants. The great tree (live-oak) near by was in parts 

 stripped to the very top. In beginning work on a tree 

 the cutters seem to aim first at the topmost leaves. They 

 prefer trees with a smooth leaf ; they eat grapes, radishes, 

 &c, and can take celery, beet, young maize, and wheat, 

 plum leaves, honeysuckle, and jessamine. Strangely 

 enough, they do not like lettuce, paper-mulberry, figs, 

 cedar, except the buds, when very hard up in winter. 

 A nurseryman, on whose grounds Mr. McCook witnessed 

 the ants at work and the scene of their former exploits, 

 told him that they even entered his desk-drawers, and 

 carried away part of his chewing-tobacco. At another 

 plantation Mr. McCook saw an immense column of the 

 ants engaged in plundering a granary of wheat. 



One of the most interesting questions for evolutionists 

 centres undoubtedly in the causes and mode of continu- 

 ance of the castes or differentiated forms of species like 

 this ant. The worker-castes are sterile, and produced 

 from eggs laid at different periods by the female ; and as 

 to a blending of castes by intermediate forms, nothing 

 has yet been seen or proved in the case of the cutting-ant, 

 after careful examination by the microscope. The lowest 

 castes of minims, in all individuals Mr. McCook examined, 

 with special reference to the mouth-organs and eyes, had 

 the same structure in equal definiteness and perfection, 

 as the larger castes. Consequently, Mr. McCook again 

 finds no way of comprehending how natural selection 

 could have produced or preserved or improved these 

 castes. May I suggest that wc know as yet too little of 

 the whole life-history of social animal communities, to 

 say nothing of their past history in time, their conditions 

 during long series of years, and the reaction of each 

 community on its surroundings, to assert that any hypo- 

 thesis of evolution admissible as a vera causa in one case 

 is inadmissible in another ? We are but on the threshold 

 of the study of the influence of social laws and conditions 

 upon human communities ; how can we expect to under- 

 stand the influence of society and common interests upon 

 specialisation in ants ? Yet there are even now several 

 possible ways of imagining the influence of variation and 

 changed conditions to have aided in producing castes. 

 May it not be that the comparative study of ant-com- 

 munities of the same species, or of different species of the 

 same genus will at length furnish a key much more valu 



able than we yet know ? How is it that nations of man 

 rise and fall, increase or decrease ? Are not all men of 

 one species ? Why are there so many castes ? If we 

 cannot answer these questions perfectly, why be dismayed 

 if we quarrel about terms as to the intelligence or reason 

 displayed by various animal forms ? There is nothing to 

 be done but for men to wait, study to comprehend the 

 nature of proof, and then patiently investigate. The 

 explanation of all difficult problems will, if we are to 

 judge by the history of science, be very simple, much 

 simpler and more illuminating than the acrobatic or the 

 prejudiced intellects would have us believe. 



G. T. BETTANY 



NOTES 

 The exhibition at Croydon, held in connection with the Con- 

 gress of the Sanitary Institute of Great Britain, has a peculiarity 

 attached to it which, though it has its advantages, is a disadvan- 

 tage to the visitor. The peculiarity is that the awards of the 

 judges will not he made known till the day of closing, viz., 

 November 8. At most exhibitions visitors have their attention 

 drawn to objects of high merit by the announcements of the 

 honours the judges have awarded ; but here, and this, too, on 

 subjects often affecting their own health, visitors can, even if 

 they care to take that trouble, only form their own opinions, 

 guided by the skilled advocacy of the attendants at the different 

 stalls. If all the objects announced in the catalogue as "essential," 

 "indispensable," "infallibly safe," and "the only ones of the 

 kind made," are really so, then the practical application of 

 sanitary science in households is in a lamentably backward 

 state, even in particulars where those who are our leaders 

 in sanitation would least expect it. It can hardly be sup- 

 posed, however, that all the exhibits shown have been ad- 

 mitted with the sanction of the Council as illustrations 

 of the subjects discussed at the Institute. There are, for 

 example, mus c stands, clocks, sausage mincers, billiard registers, 

 weighing machines, mechanical toys, flower scissors, electric 

 pens, nickel-plated goods, pantographs, bells, telephones, china 

 cements, "lightning" knife sharpeners, &c. Some of the 

 exhibits are made on principles that have been repeatedly 

 denounced ; for example, filters so closed that the filtering 

 medium cannot be easily and frequently changed are now by our 

 most experienced observers admitted to be unsafe, yet there are 

 some in the exhibition. Traps of certain construction have been 

 likewise denounced, yet they are shown. Ventilators of patterns 

 generally regarded as practically useless, and so-called disin- 

 fectants which are only deodorisers, are shown. It might, 

 perhaps, have been well had the exhibition been called one of 

 "Sanitary and unsanitary appliances, "and then the visitor would 

 have been put on his guard not to believe in everything shown 

 there. Mr. F. P. W. Essie, C.E., has contributed part of a col- 

 lection of the matei ials on which his paper on the dangers of bad 

 plumbing (read at the Congress) was based. It is intended as an 

 unsanitary exhibition, and shows in an alarming manner how 

 some so-called sanitary appliances may become a positive source 

 of danger. Each specimen exhibited " has been associated with 

 death and with diraster in some shape or other." It is a pity no 

 handbook or any kind of guide other than the unclassified list of 

 entries in the catalogue has been prepared. We may be able to 

 return to the subject next week when noticing the list of awards. 



An article in the last number of the Revue Scientiftque con- 

 tains an interesting account of Mont Ventoux (1,92s metres 

 high), and of the scheme for erecting a meteorological observa- 

 tory thereon. The project, which has been prepared by M. 

 Morard, under the direction of M. Bouvier, includes, first, the 

 construction of a carriage road, which will render the summit 

 accessible at all times. The total length will be 19 kilometres. 



