PHYCOMYCETES. 483 



been made 'to study the Bermuda species of this group critically. Such a 

 study by some resident botanist would doubtless yield interesting results. 



Sub-class 2. PHYCOMYCETES. 



The Phycomycetes are often known as the algal-fungi because of their 

 resemblance to certain of the lower algae or seaweeds. Some of the species 

 are aquatic and most of them require a very moist habitat, often producing 

 spores which are able to swim about in water. The fish-mould which often 

 causes epidemics among fish belongs to this group. 



To this group of fungi also belong the so-called white rusts which 

 occur as parasites on the leaves and stems of various kinds of plants. They 

 are called white rusts because the spores form white blisters on the leaves 

 and stems of the host plant, the blisters resembling in form those of the 

 true plant-rusts which will be considered later on. 



Many of the white rusts are very destructive parasites, and while all 

 of the species are parasitic, many of them occur on plants which are of no 

 economic importance or are not serious enough to cause any great damage. 

 Only one species of white rust has been collected in Bermuda so far as is 

 known. This is Albugo Candida, a parasite which attacks the leaves and 

 stems of plants belonging to the Mustard Family. The Bermuda species 

 was collected on the stems and leaves of the cultivated radish. 



Another fungus which belongs to the Phycomycetes is the Mucor or 

 common bread-mould. Specimens of one species of this genus were found 

 abundantly on richly fertilized soil. 



Still another Phycomycete found in Bermuda is Pilobolus crystallinus, 

 a minute fungus which grows on the dung of animals. This fungus is 

 provided with an explosive apparatus by means of which the spore-caps 

 may be thrown some distance into the air. The entire cap which is about 

 the size of a fly-speck is often found adhering to the stems and leaves of 

 surrounding plants. Since the spores of many species of fungi which 

 grow on the dung of animals are able to pass through the body of the 

 animal and keep their viability, it is not unlikely that the spores of this 

 species behave in this manner. The adhesive device may be an adaptation 

 for placing the spores where they may be eaten by cattle and other 

 herbivorous animals. After passing through the body of the animal they 

 are then ready to resume growth. 



Order 1. PERONOSPORALES. 



A single species belonging to this order has been recorded, the white 

 rust named above. 



Order 2. MUCORALES. 



Two species belonging to different genera have been collected in Ber- 

 muda one of which is listed above. 



Sub-class 3. ASCOMYCETES. 



The Ascomycetes represent a very large group of fungi of extremely 

 varied habits. Many of the plants of this group are parasites and some 

 of them very destructive, while many others live a retiring sort of life as 



