CHAPTER III. — SPORES OF FUNGI. — GERMINATION. IJ5 



it at right angles, as in Nectria Lamyi. In some of these forms, Saccharomyces, 

 Exoascus, Nectria Lamyi and its nearest allies, sprouting is the only known 

 mode of germination in the spores in which it is found; in others, as Dothidea 

 Ribesia, spores of a similar character exhibit some of them sprout-germination, while 

 others put out germ-tubes, which may or may not give off sprouts, and this is 

 the case also with the ascospores of Bulgaria inqmnans, in which the germ-tubes 

 which give off sprouts swell into vesicles as they issue from the episporium (Fig. 60). 



In the last-mentioned cases the proper growth of the tubes often ceases with the 

 formation of sprouts;- they resemble therefore the forms described above as pro- 

 mycelia, and are connected with typical promycelia by a variety of intermediate forms 

 which will be dealt with in Chapter V. 



Finally it must be remarked that the modes of germination here described take 

 place, as has been always hitherto assumed, after shedding and discharge of the ripe 

 spores ; but a number of cases are known among the 

 Ascomycetes in which the spores germinate inside the 

 ascus which has just matured, and form simple germ- 

 tubes (Sphaeria praecox, Tul, Peziza tuberosa\ or 

 form sprouts (Exoascus, Peziza Cylichnium, P. bolaris, 

 and especially Nectria). In some species this occurs 

 quite exceptionally, as in Peziza tuberosa ; in others it 

 is very frequent, as in Sphaeria praecox, according to 

 Tulasne, in Exoascus and Taphrina ; it may even be 

 the general rule, as in Nectria inaurata, Lamyi, and 

 others 1 . As in the cases last described the products, germ^iSing ! '^^rater"Tlprout S ceii? 



r • . • i • 1 1 • j p short thick germ-tube to be regarded 



of germination are numerous sprouts which are abscised as a pr omyceiium. 



and from which in Exoascus new sprouts are at once 



abscised, so in this case the ascus is often densely filled with the sprout-cells, so 



that the original spores formed after the type of the Ascomycetes (section XIX) 



are entirely concealed by them, a state of things which has given rise to all kinds 



of misconceptions. 



Historical review of spore-formation. Organs resembling the seeds of Phanero 

 gams and developing into new individuals were up to the times of Toumefort and 

 Micheli (1707, 1729) supposed notto exist in Fungi, or were at least but little sought 

 for, though it is true that a few places are to be found in older writers, which 

 speak of the seeds of Fungi. On this point Ehrenberg, Ep. de Mycetogenesi, and 

 Tulasne, Sel. Fung. Carpologia, Prolegomena, Cap. I, V, should especially be consulted. 



The development of the spores was at first examined chiefly in the larger 

 mushrooms. Micheli, Nov. plant, genera (1729), saw the spores grouped in tetrads 

 on the lamellae of the Agarici (1. c. p. 133, tt. 73, 76), but did not perceive the 

 mode of their attachment ; but he saw the asci of Tuber plainly and the spores in 

 the asci (1. c. p. 221, t. 102). Bulliard (Champ, de France, 1791) recognised the sterig- 

 mata (filets) on which the spores of the Hymenomycetes are placed, and O. F. JMiiller 

 gave an excellent account of the spore-tetrads of Coprinus conatus in the Flora Danica, 

 Fasc. xiv. in 1780 ; Hedwig, Descript. &c. Muse, frond. (1788), discovered the eight- 

 spored asci of the Discomycetes, and he and the writers of the succeeding period 

 gradually found these organs in the majority of the orders of Ascomycetes ; Persoon 



1 Janowitsch, 1. c. 

 I 2 



