204 



KNOWLEDGE 



[No\TSMBER 2, 1891 . 



Fig. I. 



Mycelium 



On the under surface of the cap are a number of gills 

 of a brown colour, disposed in a radial fashion. They 

 are not all of the same size, some running from the stalk 

 to the periphery, while others stop at intermediate places 

 on the way, but they are all disposed so that the inter- 

 spaces between the adjacent gills are kept of the same 

 breadth. Half-way up the stalk of the older specimens, 

 which we are supposed to be 

 examining, there is a collar 

 formed of a flaky material 

 which has the appearance of 

 having been torn from some 

 other body in the course of its 

 growth. It is called the 

 rein III or veil. A glance at a 

 series of specimens, ranging 

 in age from the button stage 

 upwards, reveals the origin 

 of the veil. In the youngest, 

 the gills are not visible, the 

 cap is nearly spherical and its 

 margin lies near the upper 

 portion of the stalk (Fig. I., 3). 

 The existence of a cavity 

 formed by the cap and the 

 stalk is obscui-ed by a mem- 

 brane joining the periphery 

 of the cap and the stalk. An 

 older form shows that a tear- 

 ing of this tissue is taking 

 place consequent on the ex- 

 pansion of the cap, and the 

 line of ruptiu'e is near the 

 circumference of the cap. As 

 the cap increases, the mem- 

 brane is completely separated 

 from it and is left as a frayed 

 ring on the upper part of the 

 stalk. 



The gills in the younger 

 specimens are often of a 

 delicate pink hue, while in 

 others they are whitish. In 

 fact, we are dealing with a 

 very variable species, which 

 is common in rich pastures, accoi'ding to Berkeley, in most 

 parts of the world. 



The base of the stalk is connected with a number of 

 white threads. If we carefully remove the earthy and 

 other particles from these we shall find that other stalks are 

 connected to them, so that we have a large number of 

 Mushrooms all united together by these strands. ^lade 

 up in dry patches of manure, the threads or strands' are 

 sold in shops under the familiar name of Mushroom 

 spawn. They ramify through the soil wherever these 

 forms grow. In all probability, then, there is some ^•ital 

 connection between the Mushroom spawn and the Mush- 

 room plant. 



If the cap of a Mushroom, just arrived at maturity, be 

 placed in its natural position on a sheet of paper and 

 allowed to remain there for some time in a still atmosphere, 

 it will be found, on remo\'ing it, to have left an impression 

 of its gill system on the paper, by the deposition of minute 

 dust-hke particles, which naturally suggest to one's mind 

 their connection with the gills themselves. They are so 

 minute that a hand lens is useless for their examination, 

 so we select a portion of the cap and place it in a sUt in a 

 piece of pith, and with a razor wetted in dilute alcohol we 

 cut an extremely thin tangential vertical section. Under 



(spawn) of Mushroom care- 

 fully washed. Young 

 fructifications (Mushroom 

 plants), a, are seen arising 

 on it. 2. Young Mushroom 

 cut TertieaUy through the 

 centre, showing the cavities, 

 c. into which the gills will 

 afterwards grow. 3. Longi- 

 tudinal radial section of 

 youug Mushroom at a later 

 stage than 2 ; I, gills ; v. 

 Tclum or veil ; a, younger 

 Mushrooms. 



a lens the section appears as represented in Fig. 11., 1. ; 

 under a low power of the microscope, a single lamella 

 has the appearance of Fig. II., 2. In the centre is 

 a lax tissue composed of elongated cells, and called the 

 tramii. It is bordered on both sides by smaller cells 

 which form the siih-liyiiieniul layer. Surrounding this 

 layer is a belt of larger cells, the hymenial layer. On 

 some of these may be 



\>\\e U.3 



noticed two minute 

 stalks bearing, each one, 

 a small oval body. This 

 will be better observed 

 on reference to Fig. II., 

 H, which is a small por- 

 tion of the lamella very 

 much magnified. The 

 oval bodies are called 

 spores. They are of a 

 brownish - purple hue. 

 The stalks on which 

 they arise are termed 

 steriijiiiata, and the cell 

 which bears sterigmata 

 is called a hasidium. 

 Between the basidia 

 are cells which do not 

 bear spores, but appear 

 to act as padding. 

 They are known as 

 piirapliyses. 



The spores of Ayaricus 

 caiiipestris and of the 

 Hyiiii'iiiiiiiyretes (the di- 

 vision of Fungi to which 

 it belongs) generally are 

 comparable, according 

 to some, to the gonidia 

 of the potato-disease 

 fungus, that is, they 

 have been formed asex- 

 ually. According to 

 others they are true spores, but as male and female organs 

 have never been found in this plant, apogamy (or suppres- 

 sion of the union of male and female elements) is supposed 

 to have taken place. For the sake of convenience we call 

 them spores, and the Mushroom plant on which they 

 arise, the sporojilioie. 



From the spores the Mushroom plant arises. It is 

 curious, however, that the germination of these, in the 

 particular species with which we are now dealing, has 

 never been observed, although it has been seen in allied 

 forms. In these cases there were many failures before 

 good results were obtained, these being due to conditions 

 of temperature and moisture, itc, so that far from 

 destroying our hopes in this case, we may look soon for an 

 account ol observations on the germination of the spores 

 of AyarUiis ruin just ris. 



Nevertheless, at the present time curious speculations 

 have arisen auent these spores, and the botanist's inability 

 to germinate the spores has given an air of truth to them 

 rather than otherwise. Mr. Straton, writing in Xature, 

 of 16th November, 1890, states : " The coimnon Mush- 

 room (P«(//io(« ((/wywsfra) is particularly agreeable to sheep 

 and oxen, and is abundant in autumn in rich pastures. 

 Although there is still much in our knowledge of its life- 

 history that is incomplete, yet it is evidently composed of 

 two main periods ; first, a parasitic period passed in the 

 body of an animal host ; and secondly, a saprophytic period 

 passed on some suitable organic soU. Let us sow the 



trama 



J. 



Fig. II. 1. Longitudinal section 

 of cap, showing gills (enlarged). 

 2. Magnified repre>eutation of a 

 gill of 1 ; f, trama ; s. hi/, sub- 

 hymenial layer; hi/, hymenium; 

 h. basidium. 3. Very much mag- 

 nified \ie-K of a small portion of 

 above ; j), pai-aphyses; b, basidium ; 

 s, spore ; «', developing spore ; s/, 

 sterigma; *. hi/, sub-hymenial layer. 



