LICHENS AND FUNGI OF OTAGO, NEW ZEALAND. 429 



occurring generally in the form of irregular glomeruli (fig. 54), which are com- 

 pound — made up of an aggregation of individual perithecia. These perithecia 

 are found isolated only in the young state of the plant (figs. 55, 56). They 

 are then seen to be isidiiform or sub-columnar warts, having a rounded apex, 

 marked by a sub- papillate ostiole (a), of a darker red, which leads to a flask- 

 shaped imbedded nucleus (£), of similar colour. Under moisture, the whole 

 perithecium becomes more beautiful and distinct; it swells, and assumes a 

 brighter or purer colour; the ostiole becomes quasi-pellucid or gelatiniform, 

 and much more papillate and prominent ; and the nucleus shows itself on sec- 

 tion as a viscid or gelatiniform mass, of colour resembling that of the ostiole, 

 having more of a brownish or reddish tinge than the exterior or envelope of the 

 perithecium. 



These perithecia coalesce or become aggregated in numbers of from two to 

 twenty or upwards, to form the compound glomeruli. From mutual pressure, 

 they undergo changes of shape, but they never entirely lose their individuality ; 

 for each perithecium in a glomerule may be distinguished by its red punctiform 

 ostiole (figs. 54, 58), and on section, by the dissepiments between the separate 

 nuclei. 



The glomeruli vary necessarily greatly in size and form, according to the 

 number and closeness of aggregation of the constituent perithecia (fig 53). They, 

 as well as the ostioles, also vary much in deepness of colour, being sometimes 

 comparatively pale, at other times darker, and more red or brown, than usual. 

 The ostioles, moreover, vary greatly in size and form ; sometimes they are mere 

 points — in large glomeruli of closely aggregated perithecia ; sometimes they are 

 so large and distinct as to resemble the disks of Lecanorine apothecia (fig. 58). 

 Their form is determined by that of the perithecia ; which again is regulated by the 

 amount and direction of mutual pressure in their condition of aggregation in the 

 glomeruli. In the old state, the nucleus frequently falls out, leaving an inverted 

 conical cavity of a much paler (whitish) colour than the exterior walls of the 

 perithecium (figs. 57, 59). In this state, the perithecium bears some resemblance 

 to certain species of the old Lichen-genus Gyalecta. 



The spores (fig. 60) vary considerably in their characters. Their length is 

 generally about •0006 // to -00075"; their breadth -00015" to -00025"; they are 

 colourless, and very delicate, resembling those of certain Verrucariw. Their form 

 is generally narrowly ellipsoid ; but they may be convex on one side only, and 

 straight on the other ; or fusiform ; or variously curved in the same or opposite 

 directions. Sometimes they are simple, or occupied by two to four or more nuclei 

 or granules, or with fine granular matter alone. There is, however, a tendency 

 to division of the cell- contents into two or four loculi (a.b), producing the appear- 

 ance of 1 to 3 septa ; and sometimes also there is a tendency to constriction 

 opposite the septum (a). 



