40 



straw during winter in the form of dark, linear patches ; such as you will 

 find on this sample of straw. Germinating in spring both of the cells 

 may produce short filaments bearing on the points of its several branches 

 small gobular cells known as sporidia, easily transported by the wind 

 when detached. Shortly after the leaves of the Barberries have expand- 

 ed thickened patches, dotted with minute yellow spots, may frequently 

 be seen on them. The yellow spots are clusters of a large number of 

 spores gathered together as chains in cup shaped masses and embedded 

 in the diseased, thickened tissues of the leaf through which the myceli- 

 um passes in every direction. These spores produced on the barberry 

 leaf may, after being brought in contact with growing grain or grasses, 

 again produce the red rust. I his fungus absorbing the nutriment in the 

 stem and leaves of the grain which would otherwise be stored in the 

 seed, causes the latter, instead of being entirely filled to present a 

 more or less small and shrivelled appearance reducing it some- 

 times very materially, in weight and quality. 



In order to check the development or spread of injurious fungi it 

 is important to know as much about their methods of growth and re- 

 production as possible. Even the knowledge that a disease is caused 

 by a fungus may be of great value in itself, as this would make us 

 careful to destroy or disinfect, as much as possible such materials on 

 which these organisms might be growing. The thickenings sometimes 

 seen on plum or cherry trees, known as "Black Knot" (caused by a 

 fungus) should therefore not only be cut off but burned. The know- 

 ledge that the fungoid growth appearmg on the leaves of the potato vines 

 causes later on the rot of the tuber, enables us to fight this enemy 

 before the potatoes are taken out of the ground. Much loss has also 

 been prevented by the discovery that the disease on grains known as 

 Smut, produced by the spores clinging to the seed grain can be over- 

 come by soaking the grain before sowing, in a solution of copper sulphate. 

 The pleasure to be derived from the study of this group of plants 

 is, therefore, not confined to seeing the beauty and harmony of nature 

 but may be materially enhanced by discovering something of value to 

 the human family. Many of those who use the microscope for recrea- 

 tion or amusement will doubtless find this a study well worth while 

 pursuing. 



