Vol. XVII. No, 410. 



THE AGRICULTCmAL NEWS. 



11 



He has found that the crustacean, Cyjridina, and the fire-tfj- 

 Luciola both contain bodies similar to luciferin and luciferase, 

 but that the production of light in these forms differs from 

 that described by Dubois for F/iolas. 



In the case of Cypridina and Luciola, Harvej' has found 

 in the first place that the luciferase of Dubois occurs only 

 in the luminous cells, and the luciferin is widely distributed 

 in the non-lurainnus forms. Secondly, he has been able to 

 oxidize luciferin with light production by the use of certain 

 oxidizing agents; and thirdly, Cj/ZovWiHot luciferase will give 

 light with certain substances, some of which could not possi- 

 bly be oxidized. 



Harvey therefore comes to the conclusion that it is the 

 luciferase of Dubois which is the source of the light, and not 

 the luciferin. He concludes that luciferin merely assists in 

 the production of light from luciferase. He therefore 

 { roposes to change the names of these two substances, giving 

 luciferase the name of photogenhi or light producer, and call- 

 i-ig luciferin by the name of pliidnplielein or light assister. 



Harvey gives a simple experiment to show which of 

 these two substances is the source of the light in certain 

 luminous insects. It may be remembered that in the 

 £rst part of this article (see last issue) mention was made 

 cf the fact that the two coiLmon fire-Hies of the Eastern 

 United States product' light of ditt'erent colours, Pholinus 

 siving off an orange light, while Photuris em t? a greenish 

 vellow light. This difference in colour has been shown by 

 Coblentz to be genuine, since the spectrum of Photinus 

 extends further into the red than that of Photuris. 



The two light-producing substances cin be prepared 

 from each of the two species, and Harvey found that the 

 photogenin (luciferase) of Photinus mixed with its own 

 rhotophelein (luciferin) gives an orange light, while the 

 ' photogenin of /'koturi,^, mixed with its own photophelein 

 iives a greenish yellow light. He found that it wafe possible 

 to "intercross' the light-producing substances of the two 

 species, so that the photogenin of Photinus gives light with 

 the photophelein of Photuris, and vice versa. 



Now it the source of light is photophelein (luciferin), 

 as Dubois considers, then the light produced by Pliotinus 

 (photophelein 'crossed' with Photuris pli'itogenin) should be 

 orange, the colour characteristic of /'hotinus, which supplied 

 the photophelein. Harvey found, however, that the light 

 ■rom the 'cross' is greenish yellow, and conversely the light 

 from a mixture o! Pliotinua photogenin (luciferase) and 

 PImIw is photophelein (luciferin) is orange. In each case 

 il will be noticed that the colour of the light in these 'crosses 

 '..X that characteri.>-tic of the fire-fly supplying photogenin 

 (luciferase). The photogenin, Harvey concludes, must be 

 the oxidizable substance, and the source of the light. 



Thi^ subject may be taken up again at some future 

 date, and something further said about the chemical nature 

 if these two substances, and the way in which they react on 

 )ce another. 



J.C H. 



DEVELOPMENT OF BRITISH HONDURAS. 



British Honduras is one of the tropical Briti.-h American 

 colonies that is capable of considerable development. An 

 interesting paper on this colony appeared in the Gcigrophic'd 

 ./'.urnal, September 191". The writer, Brigadier-General 

 Sir Eric Swayne, K.C.M.G., C'.B.. lately the Govercor of the 

 joloDV, point's out that British Hondinas is nearly equal in 

 ire I "to all the British West Indian islands together, but 

 lint its populatirr. of only something over 41,000 is fewer 



than five people per square mile. I^arge tracts of the interior 

 have hardly been explored as yet, and its resources have 

 not been at all adequately estimated. 



The colony had for its beginning a small crew of ship- 

 wrecked British sailors in the year 163S. These settled 

 down to cut and export logwood, the ijrofits on which soon 

 attracted new settlers. After many vicissitude- owicg to 

 Spanish attacks, the colony was left definitely in the h\nds 

 of the British at the end of the ISth century. 



The wood-cutting industry still continued to be the 

 chief interest, and even when the price of logwood fell fion> 

 £100 per ton to £S, so ihit it ceased to be profitable, the 

 forests of mahogany provided a remunerative product for the 

 wood-cutter. This has militated very seriously against 

 agricultural pursuits, as the mahogany cutter hated to- 

 exchange his free forest life for the more settled life of 

 agriculture. The greatest drawback to agriculture there- 

 fore in British Honduras, even in its more populous districts, 

 has been the want of a steady labour supply. 



Sir Eric Swayne rightly considers th\t in the develop- 

 ment of agricultural interests lies the future of the colon3" to- 

 a very large extent, and he points out that most trOfjieal 

 crops are eminently suited to its cliniitic and soil conditions. 



Efforts are being made to stimulate and encourage more 

 interest in agriculture, as the report on the Bitanic Station 

 for the year 1916, recently received at this Office, clearly 

 shows. In this report, Mr. E. J. F. Campbell, Superintendent 

 of the Botanic Station, begins by emphasizing the view 

 taken by Sir Eric Swayne, that the most serious drawback to 

 the agricultural development of the colony is the scarcity of 

 labour, largely due to the superior attraction of woodcutting. 



The coco nut industry seems to hold out great promise 

 of future importance in British Honduras, being well adapted 

 to local conditions. It is hoped that, as there are large 

 tracts of land suitable for coco-nut cultivation not utilized 

 at present, coco-nut plantations will be considerably extended 

 in the near future. The experiment plot under coco-nuts 

 at the Botanic Station is devoted to the demonstra- 

 tion of proper methods of planting and treatment. The 

 system of drainage of thi' land at the Botanic Station has 

 attracted ii yood deal of attention, and it is noted that several 

 coco nut planters have adopted a system of drainage for the 

 purpose of improving their lands, with noticeably good 

 results. Another important crop which is capable of improve- 

 ment and extension is bananas. It seems however that the 

 exportation of this fruit has considerably decreased, owing 

 possibly to crude methods of cultivating the crop. 



Mr. Campbell thinks that there are thousands of acres 

 of land in the colony eminently suited to the production of 

 rice. Practically no rice however is grown at present. 

 This also seems to be an industry capable of great develop- 

 ment. 



Among minor industries, that of the collection '"f chicle 

 gum, the produce of a species of achras very similar to th;^ 

 well-known ^sapodilla, has recently been carried out with 

 considerable profit. 



Mr. L'ampbell thinks that among other tropical agricul- 

 tural products, maize, coffee, and Para rubber, could be 

 largely and profitably cultivated in the colony, although at 

 [resent no attention is being paid to th^ni 



Amongst valuable plants introduced into the Bjtai ic 

 .Station at Belize we notice the Brazil nut (Btrthi'Ueui 

 f.ri-g/fa), and the rare palm {Loinifea ^e-hellariuii), known as 

 coco-de-mer or double coconut, from the Sej'clielles Islan;ls,r 

 two specimens of which are now growing well in the grounds. 



