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Swift Moths. 



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of ornamental pattern are sometimes used, but the question 

 of expense usually prohibits their use for cottages. A tiled 

 roof should have a pitch of not less than 40 0 . Ordinary 

 slates are a cheaper form of roof covering than tiles, but 

 should not be laid to a less pitch than 30 0 . 



There are also several artificial substitutes on the market 

 in place of tiles and slates. The asbestos-cement slates seem 

 to be rapidly rising in favour in some parts of the country, 

 but it has yet to be proved that they are as durable as good 

 Welsh slate. The advantages claimed for them are that 

 they are light, weather-proof, non-conducting, and economi- 

 cal, the cost being stated to be less than one-half that of 

 Broseley tiling. The rafters are usually spaced 2 ft. apart, 

 thus effecting a saving in the timber as compared with the 

 spacing for ordinary slates. 



This article has been devoted to the general treat- 

 ment of the subject, and has aimed at setting forth the main 

 principles on which unpretentious but useful cottages can be 

 provided for labourers at a reasonable cost, without sacri- 

 ficing comfort or durability. The accompanying designs will 

 serve to illustrate how such cottages can be erected, at the 

 prices stated, to meet the present-day needs of agricultural 

 labourers. 



SWIFT MOTHS (Hepialidae). 

 R. Stewart MacDougall, M.A., D.Sc. 



The Hepialidae are an isolated family of moths showing 

 some primitive characters. There are five British species. 

 Three of these feed — in the caterpillar stage — on and in the 

 roots and rhizomes of the bracken fern (Pteris aquilina). The 

 two troublesome species are the Small Garden Swift Moth 

 (Hepialus lupulinus, L.) and the Ghost Swift (Hepialus 

 humuli, L.). The caterpillars feed underground. 



Hepialus lupulinus. — The caterpillars of this moth are very 

 destructive; their food plants belong to many Natural Orders. 

 In the past three years the caterpillars have been reported to 

 the Board as damaging — often severely — the underground 

 parts of daffodils (the bulbs especially), peonies, dahlias, 



