June 22, 1911] 



NATURE 



569 



degree of salinity. It is impossible to discuss here the 

 various theories of fertilisation to which these astonishing 

 experiments have given rise. 



But such phenomena appear, perhaps unreasonably, all 

 the more astounding to us, as the animals experim'ented 

 on are higher in the scale ; and so we may look with 

 renewed wonderment at a phenomenon which M. Bataillon 

 has demonstrated in the frog, and M. Henneguy has re- 

 peated and confirmed.^ Eggs were taken from the body of 

 a female frog, under proper antiseptic precautions and 

 with careful simultaneous "control" experiments. The 

 eggs were placed in a little dish, and were then carefully 

 pricked with a tiny needle of platinum or a sharp spicule 

 of glass, after which they were covered with a layer of 

 water sterilised by heat. In the hands of these physio- 

 logists, the little needle was as potent (or almost as 

 potent) as Aaron's Rod. In about four hours the eggs 

 began to develop, but while all of them passed through 

 some initial stages, it was about one-fifth only that 

 segmented in the normal way. At every stage the 

 mortality was greater than in the case of ordinary fertilised 

 eggs, but at length, out of a thousand eggs experimented 

 on, one hundred and twenty hatched into tadpoles, and of 

 these three were reared through parts of their meta- 

 morphosis. They did not actually turn into frogs, but 

 died accidentally or for want of proper nourishment after 

 the appearance of their legs, and after the oldest (about 

 three months old) had all its four legs well developed and 

 its tail already beginning to disappear ; it was, in short, 

 all but a perfect frog. As with St. Denis, when he walked 

 a short distance with his head under his arm, " ce n'estque 

 le premier pas qui colite " ; but these tadp>oles, if they did 

 not endure to the end, went a long distance on their way. 



It is all but superfluous to add that the authors of these 

 researches are men of high standing and reputation, skilled 

 in all the precautions- necessary for the carrying out of 

 their experiments and for safeguarding them from all 

 sources of accidental error. In short, we may have no 

 doubt at all that what they assert they have actually per- 

 formed — that they have demonstrated the artificial fertilisa- 

 tion of a vertebrate ovum by a simple mechanical stimulus, 

 and that, so to speak, they have raised a hybrid between 

 a needle and a frog ! But here we are face to face with 

 the double role which the male plays in the process of 

 fertilisation, for, on one hand, it is his part to give 

 the initial impulse or stimulus to the act of development, 

 and on the other to convey to the offspring a share of his 

 own hereditary qualities or characteristics. In these 

 artificial experiments of parthenogenesis the two influences 

 are dissociated. The former one is efficiently replaced by 

 chemical or mechanical means, but the other drops out of 

 sight altogether. For, as a French critic has remarked, 

 " il ne pent Stre question d'h^r^dit^ du c6t^ du p^re, car 

 on ne voit pas tr^s bien les jeunes grenouilles h^ritant 

 des propri^t^s de leur ^pingle paternelle " ! 



D. W. T. 



AGRICULTURAL RESEARCH IN CEYLON.^ 

 'T*HE staff of the Royal Botanic Gardens, Ceylon, show 

 commendable activity in investigating the planters' 

 problems that come under their notice. At frequent 

 intervals issues are made of the Circulars and Agricultural I 

 Journal containing their papers, which will be found to 

 bear comparison with any publications from other experi- 

 ment stations. These papers show an obvious mastery of 

 the situation, they are conceived in a scientific spirit, and 

 exhibit none of the looseness characteristic of amateur 

 investigations into agricultural questions. Tea and rubber 

 naturally come in for a good share of attention, but other 

 crops also present their problems, many of them of con- 

 siderable interest and importance. 



As usual in subtropical countries, most of the problems 

 are connected with insect and fungoid pests, and half of 

 the present batch of publications are from the mycologist, 



1 " I.'embryogencie co iiplcte provnquie chfz les Amphibiens par p-qrt'e 

 He TcL-nf vierge," etc. Par K. Hataillon. C.R., A\r\\ 13, 1910, Arch, de 

 Zool. exp. et g^n. ^5), vi, Nov. igio ; C.R., 27 Ma'*, 'gii. 



" Siir la parthenoeenese experimentale' chfz les Amphibiens." Par F. 

 Henneeiiy. C.R., Avril •?, 1911. 



- Circulars and Agrictiltural Journal of the Royal Bjtaiic Gardens, 

 Ceylon. Vol. v. 



NO. 2173, VOL. 86] 



Mr. T. Fetch. Five root diseases of tea caused by fungi 

 are described. The commonest is caused by Ostulina 

 zonata. Lev. ; the dead tea roots show no external 

 mycelium, but only a few inconspicuous black spots ; if 

 the cortex is removed, however, white fan-shaped patches 

 of mycelium are found overlying the wood. The starting 

 points of the disease are usually the dead stumps of 

 Grevillea, which is grown among tea, and cut down either 

 for firewood or when it has grown too large. Another 

 common disease is caused by Hymenochaete noxia, Berk., 

 a fungus that attacks numerous other plants. Here the 

 mycelium is external to the root, and binds up a mass of 

 sand, earth, and small stones, thus forming a crust 3 or 

 4 mm. thick ; in the early stages the mycelium is brown, 

 whence the name brown root disease has been given ; later 

 on, however, the whole turns black. It is the commonest 

 root disease of Hevea in Ceylon, but does less damage 

 than Fames semitostus ; unlike the latter, it does not 

 spread through the soil, but only along the roots of trees ; 

 hence its progress is so slow that, as a rule, the first 

 affected tree is dead before the neighbouring trees are 

 attacked. Another root disease of Hevea, so far un- 

 common, is also described. It is caused by Sphaerostilbe 

 repens, B. and Br., and is characterised by the black or 

 red flattened strands running over the surface of the wood 

 after the cortex is removed, there being no external 

 mycelium. Acacia decurrens, which has been extensively 

 planted as a wind-break for tea or for green manuring, 

 and for more than thirty years seemed immune from 

 disease, has now been found to suffer from two root 

 diseases in addition to a " gummosis," the cause of which 

 is not yet ascertained. An agaric, Armillaria fuscipes, 

 causes one root disease, and Fames australis the other. 

 Another publication deals with canker in cacao and hevea. 

 The latter plant does not usually suffer from canker when 

 grown alone, but it is badly affected when grown in mixed 

 plantations with cacao, which serves as a permanent source 

 of infection. It is concluded that both canker and pod 

 diseases are caused by Phytaphthara faberi, Maubl. ; com- 

 plete examination was, however, made of the other fungi 

 also present. 



Mr. E. E. Green describes the extraordinary outbreak of 

 snails, Achatina fulica, that has occurred in part of the 

 island, and to which reference has already been made in 

 these columns. This snail is large, its shell being about 

 4J inches long, and weighs about 4 oz. It has only 

 recently been introduced, but it has not effected nearly so 

 much damage as might have been expected, because it 

 feeds on human and cattle excreta ; indeed, Mr. Green 

 considers that, on the whole, it is doing more good than 

 harm, and does not recommend any drastic attempts at 

 extermination. Before long the natural enemies will keep 

 it down. 



Messrs, Kelway, Bamber, and R. H. Lock give a pre- 

 liminary account of their studies on the effect of different 

 intervals between successive tappings in Para rubber. A 

 previous investigator. Parkin, obtained an increase of more 

 than 600 per cent, of latex by increasing the frequency of 

 tapping; Bamber and Lock, on the other hand, find no 

 such marked wound response, although they advise fre- 

 quent tappings from the practical point of view. 



The official correspondence with regard to cotton-grow- 

 ing in Ceylon is also published. Dr. Willis does not think 

 there is much future for the crop ; other products yielding 

 larger profits are not likely to be displaced. There is also 

 a useful account of various samples of Cymbopogon grass 

 oils prepared by Mr. Jowitt, of Bandarawela, and 

 examined at the Imperial Institute. 



ABSORPTION SPECTRA OF METALLIC SALTS ."^ 

 "T^HE present volume is desigfned as a continuation of the 

 work of Jones and Uhlor and Jones and Anderson, 

 and gives the results of a detailed study of the absorption 

 spectra of salts of potassium, cobalt, nickel, copper, 

 chromium, erbium, praseodymium, neodymium, and 

 uranium, as affected by various chemical reagents and 

 different temperatures. For the purpose of the discussion 

 some 3000 solutions have been examined. The main points 



1 "A Study of Absorprion Spectra." Dy H. C. Jones and W. W. Strong. 

 Pp. ix+ 159+98 plates. (Washington, D.C,.: 1 he Carnegie Institution, 1910. 



