CHAPTER VI. PHENOMENA OF GERMINATION. 351 



In the cases in which a supply of nutrient substance is necessary for 

 germination, the commencement of the process of germination implies a previous 

 commencement of a process of nutrition, which is only another way of expressing the 

 facts. Accordingly germination is attended by the permanent and constant increase 

 in the amount of protoplasm which was described on page 113. The germinating 

 spore behaves in the same way as a growing vegetative cell. The same thing 

 evidently takes place in the intermediate cases connected with this extreme. It has 

 yet to be enquired how far water only may be taken up from the solution in other 

 cases, for instance at the commencement of germination. 



The nutrient substances suited for germination are in most cases of the same 

 kind as those adapted to the vegetation of each species. Yet there appear to be 

 exceptions to this rule. The spores of Ascobolus furfuraceus 1 which vegetates in the 

 faeces of herbivorous animals have only at present been made to germinate on the 

 mucous membrane of the stomach of living animals. They did not germinate in 

 water or in nutrient solutions or in juice obtained by artificial means from the 

 stomach of a pig, neither in the ordinary temperature of the room nor in that of the 

 animal body. It remains to enquire how far the germination depended on special material 

 qualities of the surface of the mucus membrane. I observed similar phenomena in the 

 case of Onygena corvina which vegetates normally on the feathers of birds of prey. 

 No result was obtained when spores were sown on microscopic slides with the variations 

 mentioned above ; but there was a fine formation of compound sporophores of Ony- 

 gena on the hairs cast up by a white owl which had been kept a long time in captivity 

 and which had received the spores of the Fungus with a mouse which it had eaten ; 

 the Fungus developed on the hair from the mouse on which the spores had been 

 strewed and from no other. The development of Onygena came to an end indeed on 

 most of the hairs thus obtained, and a rich growth of Gymnoascus, not intentionally 

 sown, took its place, which perhaps drove out the Onygena. Further investigation 

 of this case is necessarily deferred. 



The formation of the germ-tubes of Protomyces macrosporus has hitherto been 

 observed only on the epidermis of Aegopodium, not in nutrient solutions. It 

 remains to be seen whether this is a similar case to those which we have been 

 considering, or one where a particular nutrient substance is required for the process of 

 germination. 



It appears from the facts which have now been enumerated, that the necessity 

 for the presence of nutrient matter in germination, as well as for certain temperatures 

 and for the changes not exactly ascertained which must take place during the state 

 of rest, are connected with analogous specific differences or adaptations in the plants 

 themselves. We can scarcely suppose that the necessity for a nutrient substance 

 depends simply on the quantity of reserve material present in the spore. This is 

 shown by the recorded observations on the ascospores of Sclerotinia Fuckeliana as com- 

 pared with the very similar spores of the nearly related Sclerotinia Sclerotiorum. The 

 latter germinate readily in pure water. On the other hand, it is obvious that the 

 spores which only need a supply of water for normal germination must be provided 

 also with the requisite quantity of reserve material. 



There are still many spores of Fungi, entire groups of them, which have never been 

 observed to germinate. Putting the spermatia mentioned in the morphological portion 



1 Janczewski in Bot. Ztg., 1871, p. 257. 



