October 14, 1897] 



NATURE 



577 



with a pure culture of Saccharomyces apiculatus, and then for 

 the remaining days of their life with sterilised grape-must. 

 Comparing the approximate number of cells of S. apiitilatus 

 originally given in the food with the great numbers of the same 

 cells gathered successively in the excreta during several days, it 

 was evident that the yeast cells had greatly multiplied. It was 

 calculated that in the droplet of must containing the .9. apiculatus, 

 with which each fly was first fed, the number of yeast cells must 

 have been about 5(X),ooo ; now, continuing to feed these flies 

 with sterilised must, the number of yeast cells expelled each 

 time from the intestine was reckoned to be from 400,000 to 

 600,000, and perhaps more. In one of these pinioned flies, that 

 lived for eight days, the yeast cells calculated for one excrttal 

 drop on the seventh day of confinement were more than 

 2,500,000 ; this fly, which had been fed originally with about 

 500,000 yeast cells, must have emitted, during the eight days in 

 which no yeast was given to it, about 35,000,000 cells. In some 

 cases, especially when excretion was not frequent, the excre- 

 mentitious droplet was one mass of S. apiculatus. There can be 

 no doubt, therefore, that the yeast cells increase in numbers 

 while inside the body of the insect. This was further proved by 

 pinioning, in the manner described, some blue meat-flies just 

 caught, feeding them exclusively with sterilised must, and ex- 

 amining all the excreta during the remaining days of their life ; 



Fig. 4. 



it was found that .S". apiculatus cells, not very abundant at first, 

 increased greatly during the succeeding days ; in these cases all 

 the yeast cells excreted were derived from the Saccharomyces 

 contained in the insect before captivity, gathered with its food 

 whilst in the free state. 



On pinioning blue meat-flies in a Petri-box, and feeding them 

 exclusively with sterilised must, .S". apiculatus appears com- 

 monly in the excreta, but rarely is S. ellipsoideus observed. 

 This may be due both to the scarcity of .S". ellipsoideus in the 

 usual food of the meat-flies, and to the struggle between the 

 various yeasts and other organisms that develop in the diges- 

 tive tube. On feeding a blue meat-fly only once with a mix- 

 ture of S. apiculatus and S. mycodernia, and then feeding it 

 with sterilised must exclusively, it was observed that at first 

 the excreta contained both the yeasts in about equal propor- 

 tions ; but gradually apiculatus had the upper hand on con- 

 tinuing to feed with must ; but if the insect was made to fast, 

 the quantity of S. apiculatus in the excreta diminished rapidly, 

 and those of the mycodernia greatly increased. This shows how 

 greatly the conditions inside the intestine of the insect must 

 influence the development of the diff'erent yeast germs. 



Some observations by Drs. Amedeo and Antonio Berlese, on 

 the internal anatomy of flies (Drosophila cellaris and common 



NO. 1459. VOL. 56] 



flies), contribute much to explain how it is that the yeasts can 

 accumulate in great numbers and multiply inside the organism 

 of these insects. It is known that the juices sucked up by 

 means of the proboscis do not go directly into the intestine, 

 but are stored up in the crop, or itigliivies, a special organ 

 which, through a long tube, communicates with the oesophagus, 

 at the upper part of the digestive tract. On examining the 

 crop of many flies, it was found replete with a syrupy liquid, 

 a concentrated sugar solution, capable of rapidly reducing 

 Fehling's solution, in which yeast cells are observable, besides 

 Det/iatium, Toruhe, Bacteria and ciliated infusoria. It is 

 probable that in the ^ugary solution contained in the ingluvies 

 (unless the solution be too concentrated to permit the process) 

 the multiplication of the yeast cells must chiefly occur. 



The experiments of Dr. Amedeo Berlese thus prove con- 

 clusively the great part that insects, especially ants and several 

 kinds of flies, take, not only in the distribution (as was hitherto 

 known), but also in the preservation and multiplication of 

 alcoholic ferments. Insects, far more than atmospheric air, 

 contribute to the dissemination of yeasts, wnicti they convey 

 rather internally than externally. There is, moreover, reason 

 for ■ believing that duting the cold season some yeasts are 

 chiefly preserved and, perhaps, increased within the organism 

 of insects. . Itai,o Giglioli. 



TEN YEARS' WORK OF THE ROYAL 



GARDENS, KEW> 



'T'nE completion of the tenth annual volume of the Kew 



-*■ Bulletin has made it desirable to publish a detailed index 



to the whole series. As the number of volumes has increased 



it has become more difficult to find the information 



they may contain on any particular subject. 



The opportunity may be taken to pass in review 

 briefly the more important subjects which have been 

 treated. This will have the more interest as the 

 period covered has been one of more than usual 

 activity in the development of our tropical possessions. 

 Kew, from its first establishment as a national 

 institution in 1841, has always been applied to by 

 men of business desirous of engaging in new in- 

 dustries. Response to individual inquiries gradually 

 came to be regarded as insufficient, and a demand 

 arose for the prompt publication for general use of 

 any information likely to be of service to those en- 

 gaged in colonial pursuits. With this object the 

 first number of the Bulletin was issued in January 

 1887. But it was also intended to serve another pur- 

 pose. When public attention is engaged by any particular sub- 

 ject, inquiries about it are numerous. To say all there is to be 

 said about it, once for all, in the pages of the Bulletin eff"ects a 

 great saving in labour. To quote the prefatory notice to the 

 first number : — 



" It is hoped that while these notes will serve the purpose of 

 an expeditious mode of communication to the numerous corre- 

 spondents of Kew in distant parts of the Empire, they may 

 also be of service to members of the general public interested in 

 planting or agricultural business in India and the Colonies." 



On March 18, 1887, the First Commissioner of Her Majesty's 

 Works and Public Buildings (Mr. Plunket) informed the House 

 of Commons : — "In response to the demands for the publica- 

 tion more speedily than in the annual report of information 

 received from abroad, I have sanctioned the publication of a 

 monthly bulletin, which can be purchased for a small sum." 



Publication was originally intended to be "occasional." It 

 has not been found practically possible to keep up an absolutely 

 regular monthly issue. This, however, has been approached as 

 nearly as circumstances would allow. 



The original intention was to confine the Bulletin to colonial 

 and commercial information. The suggestion of a larger scope 

 having been raised in Parliament, especially with regard to 

 reports on expeditions, the materials collected by which had been 

 entrusted to Kew, to notices of interesting plants or objects 

 received and the important plants sent out, Mr. Plunket further 

 decided that the "■Bulletin . . . should be made the vehicle of 

 all printed matter suitable for its pages, which it is desirable to 

 issue from Kew." As a sequel the .^«//.?/«« became, what it re- 

 mains, a continuous record ot Kew work in all its various aspects. 

 1 Reprinted from the A'e7v BulUtin of Miscellaneous In/omiation, 

 Ng. 120. 



