June i, 1909J 



NATURE 



and are free to follow the bent of thi3 or that special 

 study. In the long run, their united work is immensely 

 profitable. Here is commercial rivalry, and more ; here 

 is a better understanding of the right conditions of 

 '* applied science." 



Lord Cromer, president of the society, took as a signal 

 instance of the necessity for experiments on animals the 

 recent discovery of a serum treatment in cases of epidemic 

 cerebro-spinal meningitis, that ghastly disease which goes 

 by the foolish name of " spotted fever." It is an acute 

 septic inflammation of the membranes of the brain and 

 the spinal cord. By experiments on animals it was proved 

 to be due to special germs of the order of diplococci. 

 Flexner and Jobling, working at the Rockefeller Institute, 

 discovered a way of preparing, from immunised horses, a 

 serum containing a direct antidote, and this serum was 

 first used in the spring of iqoy. Before that time there 

 was no special treatment of the disease, and the mortality 

 ranged from 68-4 per cent, to 80-5 per cent. The children 

 — it was mostly children — suffered terribly, and died in a 

 few days ; and of those who survived many were left, 

 from the intensity of the inflammation, imbecile, paralysed, 

 or blind. By the use of the serum the mortality has been 

 reduced to 367 per cent. In Belfast, of 275 cases treated 

 before the use of the serum, 72-3 per cent, died, and of 

 ninety-eight cases treated with the serum 296 per cent, 

 died. 



The Research Defence Society exists to keep the public 

 informed of such facts as these, and we hope that it will 

 have a long record of such victories over disease. 



IS THE ASSOCIATION OF ANTS WITH 

 TREES A TRUE SYMBIOSIS? 



T^HE fact has long been known that some species of 

 ants occur in constant association with certain kinds 

 of trees. Thus members of the dolichoderid genus Aztcca 

 are often found inhabiting the interior of the stems of 

 Cecropia (icltata, and among the Pseudomyrmini P. bicolor 

 forms its nests within the spines of the " buU's-horn " 

 .acacia. The view has been held by many naturalists, 

 amongst others by Fritz MiiUer and Bates, that in these 

 cases the benefit is mutual, the tree affording both shelter 

 and sustenance to its occupants, and receiving in return 

 protection from the attacl<s of the formidable leaf-cutting 

 ants of the genus Atta and of other enemies. Doubts on 

 this point have been expressed by several authorities, 

 among them by Dr. David Sharp, in whose opinion " there 

 is reason to suppose that a critical view of the subject 

 will not support the idea of the association being of supreme 

 importance to the trees." 



A careful investigation of the relations subsisting 

 between the arboreal species of Azteca and Pseudomyrma 

 and the trees which they inhabit has lately been conducted 

 in Paraguay by Karl Ficbrig, who has published his 

 results, illustrated by numerous photographic reproduc- 

 tions, in the current volume of the Bioloi;ischcs Ceiilral- 

 hlatt.^ His conclusions mav be summarised as follows : — 



Azteca not only makes use of intcrnodal cavities already 

 existing in the stem of Cecropia peltata, but excavates 

 fresh spaces or enlarges existing ones at the expense of 

 living tissues of the tree. Fritz Miillcr described certain 

 pits in the stem of Cecropia where the wall is much 

 thinner. These spots, he says, are selected by the female 

 ant for the purpose of gaining access to the interior of 

 the stem. But, according to Fiebrig, the ants effect their 

 entrance into new internodal spaces by perforating the 

 partitions in the stem before they have gnawed through 

 the thin bottoms of the pits ; moreover, openings to the 

 exterior are often made irrespective of the situation of the 

 pits, and when the latter are perforated the boring is, in 

 certain cases, effected from within, and not frorii without. 

 Neither the internodal spaces nor the pits can therefore 

 reasonably be considered as myrmecophilous adaptations. 

 Again, the alleged orotection against leaf-cutting ants 

 must often be superfluous, since the Cecropia, with its 



1 " Cecropia pel'ala unH ihr Verhalm's 711 Altera AITan, 711 Atta sexdens 

 iind anderen InseVten. Ein kriti^cher Reilraff 7Ur Ameisenpflanzen-Hypo- 

 these." By Karl Fiebrig (San Bernardino, Paraguay). 



NO. 2070, VOL. 81] 



inmates, is apt to be found in marshy situations where 

 these eneinies cannot reach it. Most of the trees in 

 Paraguay are subject to the attacks of the leaf-cutting 

 Atta, but, nevertheless, though unprotected by the presence 

 of Azteca, they continue to maintain their existence, even 

 if belonging to introduced, and not native, species. 

 Cecropia itself is not tenanted by ants until it is some 

 years old. The presence of colonies of Azteca does not 

 prevent Cecropia from receiving much damage from the 

 attacks of other insect enemies, and Fiebrig is of opinion 

 that the constant loss suffered by the tree from the de- 

 predations of Azteca itself involves a more serious drain 

 upon its vitality than the occasional raids of the leaf- 

 cutters. Finally, the occupation of Cecropia by these ants 

 not only fails to afford protection against enemies other 

 than the leaf-cutters, but even encourages the assaults of 

 such formidable foes as woodpeckers and internally feed- 

 ing lepidoptcrous larv^. 



\Vith regard to the association between Acacia cavcna 

 and PseudoDiynna ficbrigi, the author points out that this 

 tree, in common with other species of Acacia, is pro- 

 tected against the ground-haunting Atta by the fact that 

 it grows only in situations which are constantly liable to 

 inundation. The thorns in which the ants take up their 

 abode have frequently been already hollowed out and 

 furnished with apertures of access by lepidoptcrous larva;; 

 moreover, the spaces tenanted by the ants are not con- 

 fined to the thorns, but extend also to the stem. In neither 

 situation do they occur naturally, but in both they are 

 excavated, as in Cecropia, whether by ants or caterpillars, 

 at the expense of the living tissues of the tree. 



On these grounds Fiebrig concludes that, at any rate 

 so far as the species observed by him are concerned, the 

 benefits of the association between trees and ants are not 

 mutual, but are enjoyed by the ants alone. There is no 

 doubt that the reasons for his view adduced by Fiebrig 

 are of great weight. At the same time, it cannot be said 

 that these observations are suflicient of themselves to dis- 

 prove altogether the existence of ant-plant symbiosis. 



F. A. D. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Oxford. — The following is the text of the speech 

 delivered bv Prof. Love in presenting Dr. G. E. Hale for 

 the degree of D.Sc, honoris causa, at the Encaenia on 

 June 24 : — 



Inter Astronomos qui ca quEe in ajthere solem circum- 

 fuso geruntur investigant nemini cedit Georgius EUery 

 Hale. Qui vTr duodeviginti abhinc annos primus omnium 

 fabricatiTs est instrumentum illud, ad lucis e soils puncto 

 quovis emiss^e naturam cognoscendam aptissimum, quo 

 hodie utuntur omnes fere solis observatores. Hoc sub- 

 sidio fretus potuit flammas illas excurrentes, quas^ solis 

 defectu plerumque cernuntur, sole pleno quasi in pictura 

 exprimere : mox plagas lucidissimo candore fulgentes, quas 

 faculas vocant, eodem modo reproesentare. Idem nuper 

 docuit procellis hunc a?thera vexantibus tenuissimas 

 materia particulas quasi turbine quodam agitatas vim 

 magneticam niiro modo gignere : quas omnia nemo de- 

 monstrare potuit nisi cxcogitandi peritisslmus, in obscr- 

 vando patientissimus, in causis cognoscendis sagacissimus. 

 Neque ei satis erat Natura- arcana rcserare, sed Obser- 

 vatoria duo in orbe terrae maxima fere et instructissima 

 condidit ataue ornavit : idem Ephemeridem, in qua re- 

 ccntissima de siderum natura ubique reperta pervulgantur, 

 conscribendam curavit. Sodalicium dcnique maximum in- 

 stituit quo omnes omnibus ex tcrris huius militiae ca;lestis 

 contubernales congregarentur. 



St. Andrews. — Dr. William Nicoll, who has for some 

 years carried out important researches on the parasites 

 of birds, fishes, and other forms at the Gatty Marine 

 Laboratory, has just been elected to the Ernest Hart 

 memorial scholarship. 



Dr. J. C. Irvine, lecturer on organic chemistry in the 

 I'niversitv, has been appointed by the University court to 

 I he chair of chemistry in St. Andrews, vacant by the 

 resignation of Prof. Purdic. 



