390 Illinois State Laboratory of Natural History. 



ture can be seen in the more or less distinct reticulations of its 

 surface. It is provided with slender hair-like outgrowths called 

 appendages, very characteristic of this family. These present 

 many forms, and it is from them that the generic characters 

 are mostly taken. The perithecium remains on the fallen leaves 

 over winter. It is not provided with a mouth or ostiolum of 

 any kind. The contained asci and spores only escape on its 

 decay in the spring. 



The asci are delicate, thin-walled, colorless sacs filled with 

 granular protoplasm, from which the spores are formed. The 

 latter (except in Saccardia) are simple, colorless, oblong or 

 oval cells, filled with densely granular protoplasm. In the genus 

 Saccardia, occurring on oak leaves in the Southern States, the 

 spores are septate or " muriform," and colored. 



Delicate membranaceous conceptacles, other than the peri- 

 thecia, are sometimes found in connection with the mycelium 

 of the Erysiphece. They are thin-walled, and on slight pressure 

 rupture irregularly, emitting immense numbers of minute ob- 

 long nucleated spores, immersed in a gelatinous fluid. They 

 were noticed by Cesati, in connection with the grape milde w 

 Supposing them to be independent organisms, he named them 

 Ampelomyces quisqnalis, and specimens were published under 

 that name as No. 1669 in Rabenhorst's Herbarium Mycologi- 

 cum. Later they were called Cicinobolus florentinus by Ehren- 

 berg, and Byssocystis textilis by Riess. Tulasne, von Mohl, 

 and others, finding that these conceptacles were borne on the 

 same mycelium as the conidia and perithecia, naturally concluded 

 that they were organs of the same plant, and, from their 

 analogy to certain asexual reproductive bodies in allied groups of 

 the Ascomycetes, called them pycnidia, and the minute bodies 

 they contain stylospores or pycnidiospores. This is still the ac- 

 cepted belief of many botanists. De Bary (Morph. und Phys. 

 der Pilze, III., pp. 53-75, Tafeln VI., VII.) shows that the pyc- 

 nidia instead of being reproductive organs of the Erysiphe, are, 

 in reality, the fructification of a fungus that is parasitic on the 

 Ery8iphe. Be calls it, Cicinobolus Cesatii, and gives numerous 

 figures showing its delicate septate mycelium developing within 

 the mycelial threads of the Erysiphe^ and sending up branches 

 which, by repeated division, form the cellular wall of the 

 pycnidium. 



