534 DISEASES OF CULTIVATED PLANTS 



animals have suffered, or even died from the effects of having 

 eaten the masses of spores adhering to grass, etc. In such 

 cases the injury is caused by the irritating action of the spores 

 on the mucous membrane. No active poison is present. 



Flowers of tan (Fuligo varians, Rost.) forms large crust- 

 like patches, usually of a canary-yellow colour, or sometimes 

 whitish, on tan in greenhouses, on heaps of dead leaves, etc. 

 Sometimes the plasmodium creeps over seedlings which it 

 envelops and suffocates, or it may creep up the side of a 

 plant-pot and form its fruit on the soil. The spore-mass 

 under the crust is blackish- brown and powdery when mature 

 and dry. Spores globose, pale lilac-brown, smooth, 7-11 ft 

 diameter. Not a parasite. 



INJURIES CAUSED BY ANIMALS AND BIRDS 



It is not intended in this place to discuss the numerous 

 injuries to plants caused by animals and birds, which directly 

 result in the death of the plant attacked, as when the stem 

 is gnawed through, or when a prospective crop is lost, 

 owing to mice or birds devouring the seed. There are many 

 instances, however, where the injury done is not sufficient 

 to cause the death of the plant directly, yet the wounds 

 made frequently enable fungi, insects, rain, etc., to gain an 

 entrance into the living tissues. Among such may be 

 enumerated the barking of trees by game, mice, etc., and the 

 holes made in tree trunks by woodpeckers. 



The rabbit (Lepus cuniculus) often causes serious injury to 

 young trees, especially during the winter months, by nibbling 

 away the bark near the collar, the object being to satisfy 

 hunger. 



Various preparations are on the market for smearing on the 

 stem to prevent such injury, but all such are liable to injure 

 the bark, notwithstanding statements to the contrary; wire 

 netting, although somewhat expensive, is a certain safeguard. 



The squirrel (Sciurus vulgaris) undoubtedly does con- 

 siderable damage to trees. A great deal of sentiment is 

 brought to bear on the question as to the destruction of so 

 universal a favourite, nevertheless, according to the evidence 

 of foresters, an immense amount of injury is done by 

 squirrels to seedling and young conifers. Birch and ash 

 also surfer, the bark being pulled off all round or torn off 



