98 DIVISION I. GENERAL MORPHOLOGY. 



about double their former size inside the general receptacle without any essential 

 change in their structure. A similar though less striking development is seen in 

 Eurotium, Sphaerophoron, and the Calycieae (Acolium ocellatum). 



SECTION XXIX. Combinations of the different modes of formation and 

 shedding of propagative cells which have now been described bring about the appear- 

 ance of the bodies which are often known as septate spores, but which it would be better 

 to term compound spores, sporae compositae. In their case a spore-mother-cell or 

 spore-initial-cell is developed either acrogenously or endogenously and then usually in 

 an ascus, and developes by means of one or several successive bipartitions with firm 

 partition- walls into a pluricellular body, in which each cell is an independent spore with 

 power of germination. Such a two- or more-celled body formed of spores may 

 remain persistent on its sporophore, or may be separated from it in one of the ways 

 which have been described (see Fig. 34), or may be set free from a receptacle, while its 

 members remain firmly attached to one another; and this is the case in the great 

 majority of instances, and those the most typical. In these respects, therefore, its 

 behaviour is the same as that of many simple spore-cells, which it resembles also in 

 shape and size. Moreover it happens very frequently indeed in closely related species, 

 and sometimes even in the same individual, that cells of exact morphological 

 equivalence remain at one time undivided and form a simple spore, at another time 

 become by division pluricellular compound spores. The teleutospores of Uromyces 

 and Puccinia, the gonidia of Gonatobotrys which are one-celled bodies, and of 

 Arthrobotrys which are two-celled (Fig. 21), are among the many examples of 

 this kind, and especially in countless Ascomycetes with typical 8-spored asci the 

 spore-primordia develope at one time into eight simple spores (Figs. 39, 43, 

 45), at another into pluricellular bodies, which escape in this form from the asci 

 (Figs. 46, 47). 



These facts have given rise to the phraseology which speaks on the one hand of 

 simple unicellular spores, and on the other of septate or pluricellular spores (multilo- 

 culares, cellulosae of Corda, semen multiplex of Tulasne). If the expression spore is 

 not to have a different meaning in different cases, but the same meaning in all cases, 

 and this is what ought to be, it is obvious that it can only be applied to the single 

 cell capable of germination; such expressions as pluricellular spores are therefore 

 sheer nonsense, yet to get rid of them entirely would require the establishment of a 

 perfectly new terminology, and to attempt this would be for many reasons a hopeless 

 task. The evil may be to some extent lessened by the use of the expression compound 

 spore and its correlative terms. The number of members (merispores) in a compound 

 spore is different in different cases, two in Puccinia, Arthrobotrys, and Anaptychia 

 ciliaris, three in Triphragmium, four in Phragmidium, Pleospora, and Sphaeria Scirpi, 

 &c., and they are arranged in one row or in more. 



I have several times called attention in other places l to the subject of terminology 

 which has just been mentioned, and, as might be expected, without result owing to the 

 overpowering influence of habit and want of thought in descriptive terminology. The 

 whole matter may be made perfectly clear in form and expression if we start from 

 the conception of a spore which is always presupposed in this work, and say that 

 spores are produced from their primordia (primordial cells or initial cells) and these 



Brandpilze (1853) ; Flora, 1862, p. 63. See also my ist ed., p. 123. 



