Vol.. XVIIl. No. 461. 



THE AGRICULTURAL XEW8. 



41.5 



The smaller Antillem islands afford little opportunity 

 ior research on bud rot. The cises appearing have so far 

 been few and sporadic, and the affected trees are geniTally 

 removed in haste to prevent further spread. Trinidad and 

 British Guiana are indicated as the most suitable locations 

 for the further work required. 



W. N 



EFFECTS OF ANIMAL AND PLANT PRO 

 TEINS IN RATIONS FOR LAYING HENS. 



An interesting piper on the above subject, which 

 appeared in the Philippine Agriculturist for March 1919, 

 draws some conclusions which seem well worth noting by 

 poultry keepers in the tropics. 



In the Hrsc place, it must be remembered that a hen 

 may be looked upon as a sort of living machine, which can 

 convert raw materials into a palatable and highly tiaished 

 ■nutritious product — the egg. It is necessary therefore for the 

 heii to have, besides the food necessary to maintain her own 

 bodily vigour, some extra initeriil fr un which the egg may 

 be produced. 



Kesults of c'cperimeuts as to the naUire of feeds given 

 to hens, in ord'^r to obtain a maximum egg production, seem 

 to show thar, an addition of animal protein to the food ol 

 laying hens helps much to increase the egg production 



III what rianner animal and plant proteins added to the 



of laying hens affect the lertility of the egg and the 

 vitality (if the chicks is also a question of ecinoraic impor 



tance. 



Many experiments have been made at various stations 

 in the United States with regard to the above (questions, in 

 which the feeds used were principally beef-scrap, milk, oil- 

 meal, gluten meal, and cotton seed meal. The author of the 

 paper referred to above states that these materials are not 

 readily obtainable in the Philippines, which is also the case 

 as regards most of them in the^e West Indian i.slands. 

 Accordingly, in the Philippine experiments, the animal 

 protein was supplied in the form of snails, crushed and boiled, 

 and the plant protein in the form of copra mea'. 



The experiment was conducted with two lots of twelve 

 hens and one cock each, one lot being supplied with snails, 

 and the other lot with copra meal in addition to a basal 

 ration of grain and mash. .\f all times the fowls had access 

 to green grass, ground charcoal grit, and pounded oyster 



shells. 



The experiment was conducted tor a-.year. 

 The following conclusions were reached : — 



1. The snail- fed hens were found to have fatteced 

 Tery much more than the copra nieal-fed hens. 



2. The hens fed with snails produced many more eggs 

 than those fed with copra meal. 



3. There was apparently no difference in effect on the 

 fertility of the eggs produced on either ra'ion. 



4 The chicKs produced from the copra meal fed lot 

 weie more vigorous than those from the snail fed lot up to 

 the fourth week of life ; after this time, however, the chicks 

 from the snail-fed lot began to pick up, so that theit rate of 

 growth was the same. 



'.). Tuere was no observable difference in the size of 

 the eggs produced oy either lot, the average being Jkbout .39 

 grammes in weight. ' • 



6. Mortality was greater amoug the chicks from the 

 popra fed lot than among those from the snail-fed lot. 



7. Two hens died iu the copra -neal fvl lot, while 

 none died in the snail-fed lot. 



EFFECT OF THE MOON ON PLa.NTS. 



In a previous issue of the Agricultural News a short article 

 was published on the results of a series of experiments in 

 France, which showed that planting crops at different phases 

 of the moon had no appreciable effect on the yields obtained. 

 Experiments of a .similar nature, conducted in America 

 and elsewhere, have led to similar conclusions. 



Certain notions concerning the felling of plants in 

 relation to the moon's phases have also been dissipated in 

 India (see E.xpcumenl Slation Kecvnl, Vol. XVIII, p. tU3). 



Incidentally it may bs stated that general investigations 

 hive sliown that it is not possible to place any dependence 

 upon forecasting the weather by means of the moon's phases 

 and positions. 



It is known, however, -thax the moon does have an effect 

 up'>n barometric pressure. This has been shown by German 

 invest'gations (see Expirini>:nt Sta'io/i Recotd, \o\. XXII, 

 p 417), and by certain Greenwich and Ben jVevis studie< io 

 Great Britain. 



Apparently pressure tends to be highest arnnnd the new 

 and full moon periods (i.e at thetime "of spring tides), and 

 lowest around the periods of the quarters. 



While this will no doubt influence weather 

 conditions, other f actor,^. such as equatorial and polar currents 

 ot air, are so much more potent, that the moon'.s influence 

 can never, as far as we know at present, be used in framing 

 meteorological prognostications. 



There is, however, the interesting speculation — perhaps 

 of more philosophic than practical concern — as to whether the 

 changes in the moons attra.-tive or gravitational force have 

 any important inrtuencd upjn plant physiology and soil 

 physics. 



We should imagine it most likely for an effect to be 

 noticed. in regard to the upward movement of water in plants 

 and in the soil. But to pass an opinion as to whether 

 this effect is really produced, requires a knowledge of 

 physics and astronomy. 



The main causes underlying the movement of water in 

 plant stems are, according to Palladin's 'Plant Physiology,' 

 the transpiration from the leaves, the force of imbibition in 

 the cell walls, and the c.ihesion of liquid water. The so- 

 called root pressure, produced by osmosis, which causes 

 bleeding in plants, is only involved to a minor extent. 



Tbe moon's maximum pulling influence at the time of 

 spring tides should certainly tend to cause a rise in 

 vertical columns of water, whether suspended by capillary 

 attraction (as in the soil), or by the force of folial transpira- 

 tion and cohesion (as in the stems of plants). 



On the other hand, it we are to expect high barometric 

 pressure at this [leriod. there will he an opposite tendency 

 produced, for evaporation is reduced by increase of gaseous 

 pressure. 



The subject as a wbole is a complex one, and 

 necessitates both mathematical and biological investigations 

 to obtain satisfactory conclusions. It nevertheless opens 

 up interesting speculations. 



The daily measurement of the height of columns of 

 water in capillary tubes placed under constant barometric 

 pressure and corrected for temperature changes, might 

 indicate some correlation with the change in the moon's 

 force of attraction. Sjch a correlation, if it occurs, would 

 be more readily Dot!?ed in northern than in tropical 

 latitudes. 



