ASCOMYCETES. 5 



simultaneously, and grow to about double their original size. 

 Eight is the most usual number of spores present in an ascus, 

 in a few cases four only are present, in others more than 

 eight, and then a multiple of that number, as sixteen, thirty- 

 two, sixty-four ; when very numerous and minute, as in the 

 species of Tromera, they are described as indefinite. The 

 arrangement of .spores is generally constant in a given species ; 

 unisereate, when the spores are arranged in a single row, and 

 in such cases each spore when longer than broad, usually 

 lies with its long axis more or less oblique to the long axis 

 of the ascus : in such cases the spores are obliquely uniseriate ; 

 biseriate when the spores are in two rows, usually somewhat 

 irregularly placed ; inordinate, when the spores are grouped 

 without order, often near the top of the ascus ; fasciculate, 

 when very long spores are arranged in a parallel bundle. 

 All spores are without colour at first, and many remain so 

 when quite mature, and are then described as hyaline, or 

 colourless. In others, again, the epispore becomes coloured 

 at ruaturit}-. The epispore is always smooth and even at 

 first, but in many species becomes variously ornamented 

 during growth ; when covered with very minute projecting 

 points it is said to be verruculose ; and when the warts are 

 larger and fewer in number, it is warted or verrucose. In 

 many species the surface of the spore becomes ornamented 

 with numerous more or less regular polygonal pits or depres- 

 sions, thus leaving a network of raised ridges ; such spores 

 are said to be reticulated ; when the reticulations are very 

 minute, they are liable to be mistaken for minute warts, 

 unless carefully examined, and many such spores have been 

 erroneously described as verruculose or rugulose. In most 

 species of Ascobolus the spores at maturity are of a beautiful 

 purple or rich brown colour, and marked with very slightly 

 raised lines, often running more or less parallel to the long 

 axis of the spore, and frequently anastomosing. 



In many spores the protoplasmic contents are coarsely 

 granular, an appearance which has led to their being de- 

 scribed as verruculose, even when the epispore is perfectly 

 smooth ; to guard against such mistakes, it is necessary to 

 pay attention to the outline of the spore, and not to the surface. 

 Spores vary in form from perfectly globose or spherical, to 

 filiform or needle-shaped ; in the latter case they are usually 



