1859.] CHAPTERS ON FUNGI. 297 



allied genera often appear in the form of tliin^ variously coloured 

 strata on the dead branches of trees. 



Another group presents us with an erect form, generally stipi- 

 tate, and varying in shape, being sometimes simple and clavate, 

 and at others branched in various ways. In these forms the 

 hymeniura generally occupies the whole external surface of the 

 plant, except the stem, when that occurs. 



Other Fungi again form gelatinous masses, often variously con- 

 torted, with their spores imbedded in their substance. 



In a large group of Fungi we find the hymenium occupying 

 the whole interior of the plant, and often accompanied by slender 

 branched ^occi, or threads. The external case, or coat, of such 

 Fungi is generally membranaceous^ and often, in the small spe- 

 cies, very tender and delicate. The internal mass is often soft 

 and pulpy when in a young state, and becomes dry and powdery 

 when the plant is mature ; and this powder consists of the spores, 

 which are usually very numerous. In this group the outer case 

 is denominated the peridium, and the mass of flocci (when pre- 

 sent) the capillitium. There is often also a columella, or little 

 column, in the centre of the interior. When the peridium con- 

 tains smaller bodies, which contain the true spores, these bodies 

 are generally termed sporangia. The common Puif-ball is a good 

 example of this group, but there are many variations of form. 



Another considerable group consists of small heaps or aggre- 

 gations of naked spores, generally produced on the leaves or stems 

 of living plants, and often surrounded by the ruptured epidermis 

 of the plant. Many of these Fungi are beautiful microscopic 

 objects, and though in most cases injuring and distorting the 

 plants on which they grow, often impart to them a beauty and 

 interest which they would not otherwise possess. 



The spores of this group are usually of a round shape, but in 

 some instances, as in the genera Aregma, Puccinia, etc., they are 

 elongated, septate, and sometimes stipitate. In the genus jEci- 

 dium the ruptured epidermis assumes the form of a peridium, 

 generally margined with recurved teeth, and is called by some 

 authors the pseudojjeridium. 



A numerous body of Fungi is known to us by the general 

 name of " Moulds." Under this name is comprised a variety of 

 different forms, agreeing in having a floccose base, or substratum 

 of interwoven threads, and in bearing their fruit on little pedi- 



N. S. VOL. III. 2 Q 



