THE VIOLENT PROJECTION OF SPORES 



141 



microscope a ripe spore on its horizontal sterigma was carefully 

 watched until it was discharged. One mo- 

 ment it was in view : the next it had dis- 

 appeared, but in what direction could not 

 be detected. The eye had not been able to 

 follow the motion. 



Method II. — The second method em- 

 ployed to determine whether or not violent 

 spore-projection takes place was as follows : 

 A piece of a gill, 4-5 mm. high and 2-3 

 mm. broad, was cut from a ripe fruit-body 

 of Amanitopsis vaginata and placed in a 

 vertical, but inverted, position on a tiny 

 glass shelf in a vertically-disposed compressor 

 cell. A horizontal microscope, with a magni- 

 fication of about 25 diameters, was then 

 employed to observe the fall of spores from 

 the piece of the gill when seen end-wise (cf. 

 Plate IV., Fig. 29). The gill segment thus 

 came to be so placed that the sides bearing 

 the hymenium were inclined to the vertical, 

 as shown in Fig. 51. The hymenium, there- 

 fore, looked very slightly upwards. Usually 

 it was found convenient to concentrate the 

 attention on one side of the gill, and in all 

 cases, by tilting the compressor cell held in 

 a clamp, the side in question Avas made to 

 incline distinctly upwards at a slight angle 

 from the vertical. It was argued that, if the 

 adhesive spores only drop off the sterigmata 

 passively, they would never be seen in the 

 air, whereas, if indeed they are projected 

 violently outwards, although one might not 

 be able to see them in their horizontal flight, 

 yet one should often be able to see them falling vertically at a little 

 distance from the gill surface. 



On actually making the observations, it was found that the 



FiG. 51. — Diagram show- 

 ing a piece of a gill 

 inverted and placed on 

 a tiny horizontal shelf, 

 AA, in a vertically- 

 disposed compressor cell. 

 The piece of gill is seen 

 edgewise with the hori- 

 zontal microscope. H is 

 the hymenium. S, S, 

 show the paths of the 

 spores when seen falling. 

 The spores first come into 

 view about one-tenth of a 

 millimetre from the hy- 

 menium. About 20 times 

 natural size. 



