33 



VII. — On some abnormal forms of Fungi, with remarks on their 

 Morphology. By Edwin Lankester, M.D., F.L.S., B.S.E. &c. 



(Read March 19, 1845). 



Although perhaps in the remarks I shall make in this paper I may 

 not appear to have made such use of the microscope as would 

 warrant me in bringing them before this Society, yet I feel 

 myself justified in doing so, by the fact that the general subject of 

 the Morphology of cryptogamic plants can only be prosecuted by 

 the aid of the microscope. 



Shortly after the frost which occurred in December, 1844, having 

 occasion to visit Cheshunt, I found a monstrous specimen of the 

 Agaricus personatus. It was already dried up and decaying from the 

 effects of the frost. In all its parts, however, it exhibited a normal 

 structure, with the exception of the pileus, in the centre of which, di- 

 rectly over the insertion of the stipes into the hymenium, a second 

 and smaller hymenium was developed. The gills of this smaller 

 hymenium were uppermost, and presented towards the light, the 

 edges were covered with the pileus, which gradually united itself with 

 the pileus of the lower hymenium. There was no appearance of any 

 development of the stipes (PI. ii. fig. 5, a). On making a section of 

 the whole plant, no connexion between the lower and upper hyme- 

 nium was discoverable, so that the latter was evidently an indepen- 

 dent development (PI. ii. fig. 5, c). The whole plant was in too dry 

 a state to afford a favourable opportunity of ascertaining its structure 

 by the microscope. 



On placing the upper hymenium under the microscope, it presented 

 a cellular structure like that observed in the higher forms of fungi. 

 The same appearance was exhibited by portions from the undermost 

 hymenium. The tissue was too much shrivelled to observe the spo- 

 rophores, and no remains of spores could be found on either hyme- 

 nium. Sufficient, however, could be seen to prove the identity of the 

 two structures, and that whatever was the character of the lower and 

 normal hymenium, the upper one was of the same nature. The tissue 

 between the two hymenia was found to consist of oblong cellular 

 tissue, mixed with which were the fibres of a lower form of fungus 

 which had been developed during the destruction of its congener. 



TRANS. MIC. SOC. VOL. II. D 



