August 12, 1920] 



NATURE 



757 



and other appearances which have hitherto been 

 observed only in spore mother-cells of plants and in 

 the primary spermatocytes and oocytes of animals, 

 in lettuce, therefore, there is the unusual condition 

 of all transitions between tapetal and germinal cells. 

 Dr. Gates's material also affords, in the earlier stages 

 of formation of the diakinetic chromosomes, a good 

 example of chiasmatypy — the crossing-over of two 

 members of a pair of chromosomes — which has not 

 hitherto been definitely described in plants, though it 

 is now well known in certain animals, e.g. in the 

 fruit-fly, Drosophila, in which the phenomenon has 



' n interpreted by Morgan and his collaborators 

 the probable basis of the crossing-over of factors. 

 .Another observation of much interest on the meiotic 

 chromosomes of lettutx.- is the tendency for one or two 

 pairs of the bivalent chromosomes to coalesce more 

 or less completelv on the equatorial plate of the 

 lieterotypic spindle. There, is no evidence that such 

 roalesced chromosome pairs pass over bodily to one 

 •iole of the spindle ; rather they will both split in the 

 -ual way, but the manner of their previous 



alescence will determine the nature of their dis- 

 tribution — whether;, for instance, the paternal halves 

 of each chromosome will go to the same poje or to 

 opposite poles of the spindle. There is here a possible 

 basis for the phenomena of partial coupling and repul- 

 sion, apart altogether from the crossing-over pheno- 

 mena, which latter are based on relations between the 

 two members of a pair of chromosomes in their earlier 

 l)ost-synaptic stages. 



In vol. xvii.. No. 4 (October-December, 1919), of 

 the Bulletin of the Imperial Institute Mr. W. Bevan, 

 Director of Agriculture in Cyprus, continues his 

 account of the agricultural industries of the island. 

 Among the more interesting products discussed by 

 Mr. Bevan are fodders and feeding-stuffs (including 

 the carob bean), essential oils and perfumes, oils and 

 oilseeds, fibres (including cotton and silk), drugs, and 

 tobacco. Certain minor agricultural industries are 

 also described. The reports of recent investigations 

 .-It the institute have reference to fibres from India, 

 Africa, and the West Indies, the utilisation of New 

 Zealand hemp-waste, Pappea seeds from South Africa 

 as a source of oil, Cyprus castor-seed, and distillation 

 trials with talh wood (.If aria SeyaV) from the Sudan. 

 The general articles include an account of the present 

 position of Para rubber-seed as a source of oil and 

 feeding-cake, in which it is pointed out that the 

 possibility of exploitation very largelv depends upon 

 the cost of collecting the seed on the plantations. A 

 further article deals with cassava as a source of indus- 

 trial starch and alcohol. As usual, much useful 

 information is recorded as notes and in the section 

 devoted to recent progress in agriculture and the 

 development of natural resources. We observe that 

 H.R.H. the Prince of Wales has arranged for a 

 selection of the presents and addresses received during 

 Ills visit to Canada to be exhibited at the Imperial 

 Institute. An index to vol. xvii. of the Bulletin is 

 included in this part. 



In many respects we pay too little attention to our 

 \\est Indian Possessions. The present difficulties of 

 NO. 2650, VOL. 105] 



communication hinder visits from our own men of 

 science, and it is natural that those of the neigh- 

 bouring United States should undertake tasks that Wf 

 regretfully leave undone. Thus we learn from the 

 Report of the .American Museum of Natural History 

 that towards the end of last year Mr. H. E. Anthonv, 

 who had previously secured many interesting mam- 

 malian remains from the caves of Cuba and Porto 

 Rico, extended his researches to Jamaica, whence the 

 skull of a marine mammal was the only example 

 known. His hunt was successful, but the collections 

 remain to be worked out. They are certain to throw 

 light on the nature of former connection with the 

 mainland. That we are not altogether idle may, how- 

 ever, be gathered from the fact that a collection of 

 fossil sea-urchins from Antigua and Anguilla, made bv 

 Prof. J. A\'. Gregory some years ago, was reported on 

 by Dr. J. Lambert, of Troyes, during the war, and is 

 now being arranged in the geological department of 

 the British Museum. That department has also been 

 presented by Dr. C. T. Trechmann with an excellent 

 dried specimen of the recent crinoid Holopus, rare 

 because it grows under ledges of reef-rock and so 

 escapes the dredge, instructive because of its adapta- 

 tion in form to that peculiar position. This individual 

 comes from Barbados, on which island Dr. TrecTi- 

 mann has recently spent some months investigating 

 the raised reefs and collecting their fossils. None 

 the less, the West Indies still present a large field for 

 research, and British labourers are all too few. 



The Agricultural News of May 29 has an article 

 on camphor-growing in the British Empire, based on 

 a contribution by ProL P. Carmody, formerly Direc- 

 tor of Agriculture in Trinidad, to the Times Trade 

 Supplement. The chief source of commercial cam- 

 phor is Formosa, and the Japanese monopoly has 

 led to an enormous increase in price in recent years. 

 Various, but so far not commercially successful, 

 attempts have been made in camphor cultivation 

 within the Empire, namely, in Ceylon, the Federated 

 Malay States, Mauritius, and the West Indies; in 

 some cases distillation tests have shown a satisfactory 

 yield, but in Mauritius and the West Indies the 

 prunings may yield only oil and no solid camphor. 

 Experimenting in Trinidad, Prof. Carmodv found 

 that trees grown in the Botanic Garden made verv 

 poor growth, but when transplanted to better soil 

 the growth was satisfacton,-, and a normal yield of 

 solid camphor was obtained. It is suggested that, 

 owing to their bushy, evergreen habit, camphor-trees 

 might be used as a windbreak in cacao cultivation. 

 The successful cultivation of camphor within the 

 Empire is no longer doubtful if a few necessary pre- 

 cautions are adopted. Seeds or seedlings from trees 

 that yield no solid camphor must not be used ; stiff 

 clay soil must be avoided ; in good average soil not 

 more than 300 trees to the acre should be grown ; and 

 a sufficient area should be cultivated for economical 

 distillation. When the trees are four or five years old 

 they can be clipped, and thereafter three or four times 

 a year. The same journal directs attention to the 

 development of other sources of camphor, namely, 

 rosemary in Spain, species of .Artemisia, and the 

 swamp-bay {Per sea pubescens) in California. 



