EXPLANATION OF PLATES 273 



hours from a vertical section of the pileus. Each half-tube has liberated spores 

 throughout the whole length of its hymenium-bearing surface. Natural size. 



Fig. 29. — Measurement of the rate of fall of spores. The observer is looking 

 through the horizontal microscope at a field focussed below the gills of a piece of 

 pileus contained in a vertically-placed compressor cell held in a clip. The cell is 

 illuminated by diffuse daylight reflected from a glass roof to the eye by means of 

 a mirror. On the table to the right is placed a drum driven by electricity. The 

 chronometer at the back is used for making time-records. The small battery on 

 the right of the drum is connected with the fountain pen which touches the drum 

 paper as the latter revolves, and also with the tapping-key upon the knob of which 

 the observer has his first finger. As a spore passes the three eye-piece lines in 

 the field of view, the observer makes three successive taps upon the tapping-key. 

 The fountain pen in response makes three deviations from its normal course on 

 the paper. Each spore record is afterwards measured on the drum by means of a 

 steel tape. 



Fig. 30. — Amanitopsis vaginafa. A fruit-body photographed in a wood. 

 Magnification about i. 



PLATE V 



Figs, all of Polyporus squanwsus. 



Figs. 31, 32, 33, and 34. — Successive stages in the development of two fruit- 

 bodies grown on a log in the light. Natural size. 



Fig. 31. — One day old. A stromatous knob half hidden in a rift of the log has 

 developed four conical processes. 



Fig. 32. — Two days old. The four conical processes have become fiattened at 

 their ends in preparation for the development of pilei. 



Fig. 33. — Three and a half days old. Two of the conical processes have 

 ceased to grow ; the other two have become converted into young fruit-bodies. 

 These have obliquely-placed stipes, and their pilei, which at first were sym- 

 metrically developed, already show distinct signs of eccentricity. The growth of 

 the stipes has raised the pilei so that their upper surfaces have now come to lie 

 in a horizontal plane. 



Fig. 34. — Nearly five days old. The eccentricity of the pilei and their growth 

 in a horizontal plane have become very marked. The posterior sides of the pilei 

 are in contact and have now ceased to develop. The stipes have attained their 

 maximum size. 



When seven days old the fruit-bodies were fully extended and shedding spores 

 abundantly, although the hymenial tubes had not yet reached their maximum 

 length. The left-hand pileus had become 11 cm. wide from the posterior to the 

 anterior edge, and the right-hand one 9 cm. wide. When looked at from above, 

 both pilei appeared very eccentric and resembled the pileus shown in Fig. 4 in 

 the text (p. 28). The last stage is shown in Fig. 34 in the text (p. 84). 



Fig. 35. — Young fruit-body about three days old. It has developed from the 

 only conical process produced by the stromatous knob. The pileus is very 

 centric. Natural size. 



Fig. 36. — Stromatous knob giving rise to a number of conical processes in the 

 dark. Natural size. 



S 



