CLUSTER-CUPS. 3 



'some knowledge of their generic and specific dis- 

 tinctions. 



It is exceedingly diflScult to give a logical defi- 

 nition of what constitutes a fungus. It is no less 

 difficult to furnish a popular description which shall 

 include all and nothing more. If, for example, we 

 particularize the spots and markings on the leaves 

 and stems of herbaceous plants, so commonly met 

 with from early spring till the fall of the last leaf, 

 and even amongst the dead and decaying remains 

 of the vegetation of the year, we may include also 

 such spots and marks as result from insect depre- 

 dations or diseased tissue. It is not always easy, 

 with a cursory observation under the microscope, 

 to determine whether some appearances are pro- 

 duced by fungi, insects, or organic disease : expe- 

 rience is the safest guide, and until we acquire that 

 we shall occasionally fail. 



If we take a stroll away from the busy haunts of 

 men, though only for a short distance, — say, for 

 'example (if from London), down to New Cross, 

 — and along the slopes of the railway cutting, we 

 shall be sure to find the plant called the goatsbeard 

 [Tragopogon pratensis) in profusion. In May or 

 June the leaves and unopened involucres of this 

 plant will present a singular appearance, as if 

 sprinkled with gold-dust, or rather, being deficient 

 in lustre, seeming as though some fairy folk had 

 scattered over them a shower of orange-coloured 

 chrome or turmeric powder. Examine this singular 



B 2 



