Vol. XIV. No. 333. 



THE AGKieri/IVKAL M'.Ws. 



13 



larvae, become dry and discoloun I tvl aitheleat opens out, 

 [give to a badly attacked tree a very unsightly appeal 

 ance. In addition, the effect of a serious attack i- very 

 injurious t" the tree. 



This insed is controlled to a large extent bj two 

 h\ menopterous parasites. 



A. number of moth and butterfij larvae also feed upon 

 the coco-nu1 leaves, bul these an pests of a rather local 

 nature Two of these, Brachartona :atoxintha ami Hidan 

 va, occur in other parts of the East; while two others, 

 Padraona chrysozona, and Thosea cintreomarginata occur 

 in the Philippines. 



Brassohs isthmu, which occurs in Panama.and B. topho 

 rat in British Guiana, are two other leal eating insects included 

 i ! Iir list. 



Omiodes blackburni, which is known as the palm leai 

 roller in Hawaii, is also mentioned. 



Locusts are recorded as occasional serious pests in 



Madagascar, .and the author states that in Mindanao he has 



seen coco-nuts thoroughly stripped by these insects, and so 



[]j injured thai the fruiting would be delayed two years. 



Another Orthopteron, Graefea cocophaga, .me of the 

 walking sticks, or stick insects, has at times been a pest in 



certain places. 



Its distribution extends from New South Wales north- 

 ward anil east ward across Polynesia. It feeds on coco-nuts, 

 and has temporarily done considerable damage in places. It 

 is large in size — about 20 centimetres (8 \ inches) in length — 

 bul is inconspicuous on account of its colour. 



Of all the scale insects, some thirty species, recorded as 

 attacking the coco-nut, Aspidiotus destructor is stated to be 

 the only one which is ever found in large numbers and 

 charged with doing serious damage. A. destructor is 

 probably found in every land where the coco-nut is grown. 

 It is said to have been most serious in the Caroline Islands, 

 where the coco-nut is the staple crop, but its occurrence is 

 universal in coco-nut-growing districts, and while often kept 

 in check by its natural enemies, it may at any time become 

 sufficiently abundant to be a serious pest. The lady-birds 

 of the genus Chilocorus appear to be the most efficient 

 of its natural enemies. Trees that are growing under suitable 

 conditions are less likely to be seriously attacked by 

 this pest. To guard against injury by it trees should 

 be amply spaced, provided with plenty of water in the 

 ground, and, if necessary, cultivated and manured. It is 

 led that in Trinidad Aspidiotus destructor is often pro- 

 tected by an ant (Aztecta charifex), in such a way that the 

 scale is completely guarded against its natural enemies. 



The miscellaneous pests of coconuts include such forms 

 as the robber crab (Birgus latro), parrots and crows, bats, rats, 

 bandicoots, porcupines, hogs, and bearst The hog is said to 

 lie the worst pest of all these, destroying seed nuts which 

 have been planted out, ami young trees. In the Malay 

 States, bears, pigs, and rats are said tV> do more damage to 

 coco-nuts than the beetles. In Lower Perak, bears recently 

 destroyed more than 1,000 coco-nut trees in one year. 



The article is reproduced herewith, a- being ol 



interest to West 1 1 1 ■ 1 1 . i r i agriculturists. 



The work of breeding new flowers, fruit- and \. ta 

 from natural or artificial en es, has been, and [ believe can 

 still be, carried out excellently with a minimum of Mendelian 

 theory. The most important idea, I think, is thai of prepo 

 fence, or transmitting power, or strength of heredity, as it i 

 sometimes called. This rather loose term, so far as] bav< 

 seen, has Ween used to embrace at least the following different 



Mendelian cases: 



(1) The dominam t a character in a first-generation 



hybrid. (The dominanl parenl is prepotenl for the character.) 



(2) The presence in the prepotent parent of a number 

 of separate dominant characters, or of a number of char 

 acters inherited as a dominant unit. (An important case of 

 prepotence.) 



(•'!) The excess of dominant s, from the cross of a positive 



homozygote with a recessive, over those from the cross ol 

 a heterozygote with the recessive. (The pure-bred is more 



prepotent than the i grel.) 



Ill The presence of the dominant character in all thi 

 progenj of the Lack cross of a hybrid with its dominant 

 (prepotent) parent, whereas only a fraction shows the 

 recessive character when the hybrid is crossed with the- 

 recessive parent. 



(5) In cases of imperfect dominance, the difference in 

 appearance, as well as in transmitting power, between the 

 homozygous dominant and the heterozygote. (Recognition 

 of prepotence by external characters, i 



(6) The large excess of dominants in the progeny of 

 selfed hybrid plants. (Influence of the prepotent grand- 

 parent.) 



(7) The constancy of a selfed homozygous dominant 

 compared with a hybrid. (The former is prepotent.) 



(8) The constancy of a selfed recessive compared with 

 a hybrid. (The pure-bred has greater transmitting power.) 



If, then, the breeder of improved plants uses pedigreed 

 lines (centgener plots, or ear-row tests) instead of mixed cul- 

 tures, and selects in each generation the plants which are 

 most prepotent for the pirticultr characters he needs, he can, 

 I think, usually leave Mendelian formulae to those who are 

 working to discover new facts. 



PREPOTENCE IN PLANT BREEDING. 



In tlie Journal of Heredity for January L915, 

 there appears an article under tie' title given above. \<\ 

 Mr. John Belling, B.Sc, sometinn Science Master at the 



Grammar Scl I in St. Km- and foVseveral years past 



..ntlie stall' of tin- Florida Agricultural Experinenl 

 Station, 



THE INFLUENCE OF FOOD POOR IN 



LIME ON THE COMPOSITION 



OF GROWING BONES. 



In the Monthly Bulletin of Agricultural Intelligence, 

 October 1914, of the International Institute of Agriculture, 

 there is a review of an article in the Berlin Biochemisc/ie 

 Zeitschrift, July 29, 1913, by Stephan Weiser, on this subject, 

 which gives some striking facts. 



The writer kept a group of three young pigs, from 

 January I"' to October I, on food rich in lime, and another 

 perfectly similar group, on rations poor in this substance. 



After the animals were slaughtered, theliones were analysed. 



It was found that the rations deficient in lime so affected tin 

 development of the animals that from the beginning their 

 increase in weight was about 20 per cent, less than that of 

 those fed on food rich in lime. The prolonged want of lime 

 always caused diminished appetite, and consequently diminish- 

 ed live weight. The pie- 'hat had not lieen fed with enough 

 lime had, in general, deformed, pliable bones, thinner ami 

 easier to cut than those ot the other lot; thej also contained 

 considerably! water, and much less ash. 



