IRISH GAKDENING, 



25 



mv tlu'V not':'), ina.siuueh as tla-ir larva', wliicli 

 ck'velop' from tlic rggs wlucli are often depo-siti'd 

 near a cluster of apliicU's, feed voraciously on 

 these extremely troul)les()me plant lice. A speci- 

 ally interesting group is tlic so-t-ailed ichneumon 

 fly! These " Hies " deposit their eggs within the 

 bodies of caterpillars, feeding on cabbages, &c. 

 From the eggs arise short, whitish grubs wiiieh 

 feed in the ulterior of the caterpillar, and only 

 affect the vital parts as a rule, after the caterpillars 

 liave stopped feeding. 



At tills stage the caterpilhus may l)e ol)serve(l 

 (in wails, trees, (fee, and emerging from them tlu' 

 grul)s, wliicii spin tiieir '■ cocoons " and change 

 into chrysalids, from whieii, in the spring, the 

 next generation of ichneumons arise. The chry- 

 salids of these " flies " can easily be distinguished 

 i)y being pale yellow in colour, just less than a 

 (luarter of an inch long, and about a twentieth of 

 an inch in diameter. Th(>y are usually found con- 

 gregated in clusters, and ought to be taken care 

 of ratlier than squashed as is so often the case. 

 Tlie eaterpillars thus attacked usually die. 

 Amongst other useful forms of life in the soil are 

 certain beneficial bacteria of which there are 

 various forms, some of wdiich bring about chemical 

 changes in manurial elements in the soil, chang- 

 ing by a series of processes annnonia, &c., into 

 nitrates — a partieidarly valuable plant food. 

 Others fix the free nitrogen of the air, and make 

 it available for the use of plants; others again fix 

 themselves within the roots of leguminous plants, 

 sucli as peas and beans, causing as a result of 

 their occupation the development of the nodules 

 to b(> found on the roots of such plants. This 

 group of bacteria also obtain the nitrogen from the 

 air and the plants benefit accordingly. Other 

 groups of bacteria, as also certain fungi, bring 

 about the decay of organic substances in the soil, 

 thus setting free certain plant foods which would 

 otherwise be " locked " up. 



Generally speaking, the useful liacteria only 

 develop rapidly and work efficiently in well- 

 drained, wt^ll-aerated, and limed soils, or. in other 

 words, thoroughly cultivated soils. 



W. H. J. 



(To hi' rrnifiniird .) 



Points for Plotholders. 



Dig Deep and Save Manure. — Stable manure 

 and niaruire from the byre are now very difficult 

 to obtain, and not a few plotholders will be 

 worrying over the lack of both. Under present 

 circumstances it cannot be too strongly empha- 

 sised that deep cultivation and light manuring 

 are far better than surface scratching and heavy 

 maiuuiug. Every soil contains a large amount of 

 plant food, but it is not in a form available for the 

 plants vintil the soil has come under the influence 

 of air. It is a well-know^n fact that under normal 

 conditions of nioisture the top few inches of soil 

 are the most fertile because they are directly 

 under the influence of air. To render the subsoil 

 fertile dig at least two feet deep, loosening and 

 breaking up the soil so that air can penetrate 

 d 'cply and so that, following the fertili.sing effect 

 of the air. the roots of tiie plants can rtimify 

 freely in search of food. Deep cultivation in 

 winter and spring and constant surface cultiva- 

 tion all summer will, in a large measure, com- 

 pensate for lack of farmyard manure. 



Sow A.\U TltV.NSil'hANT To l';cONOMlSE SEED.- — 



\\ lienever pos.sible it is better to sow a small 

 (iuantity of seed in boxes or in a seedbed and 

 transplant rather than soav a large quantity of 

 seed in lines and finally have to thin out more 

 than half of the seedlings. It is, of course, 

 customary to make seed l)eds for all such things 

 as Cabbages, Cauliflowers, Sprouts, Kale, Aic, 

 but there is no reason why the same shoidd not 

 be done for, say, Onions. Onions sown in a box 

 early in February would be ready to transplant 

 on to the plot by the middle or end of April, and 

 would be much in advance of seedlings from seed 

 sown in the open in March. The box need not be 

 more than thiee or four inches dee]>, and of any 

 convenient size and shape. Openings must be 

 left in the bottom for drainage, placing over them 

 some cinders or broken bricks to prevent clogging. 

 Make the soil fairly fine, especially on the surface, 

 and moderately firm, neither as hard as a brick 

 nor so loose that it will dry out rapidly. Sow 

 thinly and cover the seed with a quarter of an 

 inch, not more, of fine soil, then give one good 

 watering and cover the surface with a sheet of 

 brown paper until the .seedlings appear. The 

 box may be kept in an outhouse, or even a kitchen 

 window^ until the seeds germinate, and should 

 then have all the light possible. As the seedlings 

 develop give them water only wdien the soil is 

 dry, and encourage them to make sturdy growth 

 by putting them outside in mild weather, taking 

 them in at night or in case of cold frostv winds. 



tilANT SNOWniSOl" ( r.VL.VNTIU'S El.WI.SIT. 



(SCO p. 20.) 



