April i, 1885.] THE TROPICAL AGRICULTURIST. 



78i 



of a poor plant which grows on the English coast. The i 

 them attack only one. species. Not much, however, is 

 gained from this limitation of their ravages, fur hardly 

 anything is free from attack by one species or another. 

 This is particularly the case with the large stock of young 

 palms. Mauritia flexuosa and Arecu catechu I find it very j 

 difficult to raise at all. To keep the scale down by hand 

 washing is an endless task. I have tried the emulsion re- 

 commended for the orauge scale, made of oil, milk and 

 soap, but it has to be used with great care. If strong 

 it kills the plaut when washed from the leaves into the 

 heart, and if weak it does not kill the scale. All palms, 

 too, will not bear it of the same .strength. I find the 

 best plan is to dip the foliage of the plant in, and then 

 lay the pot dowu on its side to prevent the solution 

 draining into the heart, washing it off with soft tepid 

 water the next day. Caterpillars are very destructive, too, 

 to palms if not watched for closely, hut chiefly to the 

 larger plants in tubs and to those planted out. A kind 

 that is bred on the almond shade trees in the nursery, 

 and which travels to other plants near, is one of the 

 worst. In the propagating house caterpillars, and these 

 the smaller kinds, only affect ferns. Scale and different 

 kinds of mealy bug attack several kinds of orchids too. 

 An excellent report by Dr. McTjachlau on specimens of the 

 local orange and lime tree scale which I sent home for 

 examination, was received by the Government from the 

 Colonial Office, and published in the Official GazMe some 

 months ago. The scale of this colony appears to he a 

 distinct insect from that which is so destructive to orange 

 trees in the Southern United States, and Dr. Victor 

 Signoret, to whom Dr. McLachlan submitted my specim- 

 ens for his examination, has named in Viaspis ain-anlii, 

 it being before an uudescribed species. It attacks alike 

 oranges, limes, and the Indian bhal — JEale marmtlos — but, 

 here at least, seems to damage most the former. [Who 

 first described Helopeltis antonii? — Ed.] 



Econonic Plants. — The following economic plants among 

 others of less importance have been propagated in the 

 nursery in more or less quantity: — 



Coca. — Seed of this is now produced plentifully by the 

 plants in the gardens. It has to be watched carefully as 

 it ripens, for birds are great devourers of it. The fruiting 

 season is during the summer months. On a visit to the 

 Pomeroon Kiver I obtained seed of another species of 

 Erythroxylon, which I found about Indian settlements, and 

 as plentifully laden with seed as the coca is here in its 

 season 



Cocoa. — A good supply for propagation of very excellent 

 cocoa seed was obtained by the good services of the Com- 

 missary of the district, Mr. Harcourt, from the Berbice 

 River. It consisted principally of two varieties, with a 

 few pods each of two or three other forms. The collection 

 appeared to include the best forms grown on the islands. 

 Taking them in the order of their quantity, I made the 

 following notes on them. 1. — A large pale-yellow, deeply 

 ribbed and rather corrugated pod, sharp-pointed and ovate- 

 lanceolate. 2. — A large yellow pod, turning brown, smooth, 

 with very shallow ribs, ovate-oblong, acute-pointed. .'1. — A 

 shorter pod than number 2, which it otherwise much re- 

 sembles, but the ribs are rather less distinct. 4. — Is perhaps 

 the same as number 3, but the pods have a distinct ap- 

 pearance, and are dark brown. 5. — Perhaps a form of 

 number 1, but the pod is a bright reddish colour. Numbers 

 1 ana 3 seem to be the best kinds; their pericarps are 

 thin, and they have rather more seed than the others. 

 Mr. Harcourt sent me several lots, and in each case the 

 kinds bore the same relative proportion to each other. 

 Old cocoa trees are found, grown almost into forest, both 

 on the Berbice and Canje Rivers. They are of course 

 the remnants of old plantations. Their healthy and robust 

 growth indicates how well the cocoa industry would thrive 

 on the banks of the rivers of this colony, and it is interest- 

 ing to know that a few plantations are being established. 



Kola-nut. — The west African kola-nut, which is very ex" 

 tensively used by the natives as a masticatory, it having 

 the quality of stimulating the flavour of, and, as well 

 allaying the natural craving for food, and about the pro- 

 perties of. which a great deal has of late been written, 

 has been obtained by seed from Jamaica. A plant was 

 also received from Kew. In Jamaica it is a naturalised 

 tree, known by the name of Bissi or Bischi, and was prob- 



ably first brought to the island by slaves. Of the plants raised 

 from the Jamaica seed I have distributed publicly a few; the 

 rest I have planted as stock plants for the gardens. 



Ceard-rvbier. — I am indebted to the Manager of Smyth- 

 field, Berbice, .Mr. W. II. Qnincey, for two plants of the 

 ceara-rubber tree; and a packet of seed has since been 

 received from Dr. Trimen, the Director of the Ceylon 

 Botanic Gardens. The larger of the plants received from 

 Mr. Quincey is now over eight feet high, and growing 

 rapidly. As I pointed out in describing the tree in my 

 first Indiarubber Report, an immense area in this colony 

 is well suited for its cultivation. 



A new Cahbaye-palm. — It is generally supposed that the 

 cabbage palms in Georgetown are all of one species— 

 but I find they consist of three, though of two of these 

 the specimens are few. When first I came to the colony, 

 a plant that was growing at the Alms House on the 

 Brickdam, struck me as apparently distinct from Un- 

 common species; but it was subsequently cut down, and 

 the matter passed from my mind, till one day a few months 

 ago, when riding down New Market Street for the first 

 time, I noticed in an ally belonging to the corporation, 

 two or three large trees of the same, in full Sower and 

 fruit. Mr. Hill, the Town Superintendent, very kindly 

 allowed me to gather full sets of specimens for examin- 

 ation, the flower and fruit of which showed it to be a 

 perfbctb/ distinct type. The third, which is well distin- 

 guished by habit, I have not been able to procure flower- 

 ing specimens of as yet ; all the trees I have found 

 being too high for their heads to be reached, even with 

 the aid of a long ladder. Of the second species I have 

 raised a good stock from seed, and a very fine young 

 tree, fifteen feet high over all, and two feet six inches 

 in circumference of stem, has been successfully transferred 

 to the gardens from a yard on the Brickdam, where it 

 was found growing. These three cabbage palms are all 

 species of Oceoiloxa or Euterpe. The common cabbage palm 

 of the islands I have repeatedly tried to introduce by 

 importing seed, which, however, in each instance, failed 

 to germinate. Success however has attended the import- 

 ation of plants. I am indebted for these to Mr. F. Gurney. 

 of St. Felix, Grenada, who was good enough to send 

 several in a case of ulants native of that island. — G S. 

 Jenman, Government Botanist and Superintendent Botanic 

 Gardens, 19th June 1884. 



PI-ANT IMPROVEMENT BY HYBRIDISATION. 



A subject of much more than ordinary importance 

 was brought before the Royal Society at its last monthly 

 meeting by Mr. Pink, of the Botanic Gardens, who read 

 a paper on the hybridisation of plants. In new countries 

 this matter has a special interest; it is, of course, easy 

 enough to introduce the fruits and other products of 

 obler countries, and many of them thrive and give good 

 returns to the cultivator, but too often they do well 

 only for a time, and then begin to deteriorate, sometimes 

 very rapidly. An instance of what may be done by 

 careful selection of plants, good cultivation, and hybridis- 

 ation was mentioned by Mr. Pink in his paper. The first 

 apple-trees planted in America by the early colonists 

 retrograded until the fruit were no better than " crabs.'' 

 Now their apples are equal to any in the world. He 

 might have gone further had he been treating the subject 

 more fully, but he was dealing with improvement in the 

 product apart from the question of resistance of disease. 

 Pursuing it another step or two an additional advance 

 can be shown ; for, whereas the apple-tree is in an 

 extraordinary degree the victim to what is commonly 

 known as American blight, varieties have been produced 

 which are so free from its attacks that, when surrounded 

 by other trees whose stems and branches are completely 

 covered with it, they are quite clean. Many similar 

 examples might be adduced, but it is unnecessary to go 

 further, and we come hack to the point from which we 

 started — that hybridisation, combined, of course, with 

 careful selection and good cultivation, is the key which 

 will unlock the door and bring to light the secret by which 

 diseases in plants of all kinds may be modified, if not 

 overcome, the produce improved, and the cultivation of 

 grain crops, fruits, flowers, and vegetables made remunerative. 

 Our finest cabbages and cauliflowers are the descendants 



