FUNGI PARASITIC ON BUTTERFLIES. O 



from the chrysalids, showed the fungus to be more developed 

 than they were in the first specimen examined, in which the 

 butterfly seems to have matured more rapidly than its parasite. 



On page 171 I remarked that the lobes of the najn fungus 

 had probably become distorted in drying ; this is not an exact 

 explanation, the time the butterfly had been dead having little 

 or nothing to do with the contraction of the lobes, which seems 

 to be characteristic of this and some other forms — the oleracea 

 fungus for instance. The contraction of the lobes affords an 

 interesting case of the production of mechanical effects by a 

 slight physical modification (shrinkage) of the parts concerned ; 

 the function in this instance being to facilitate the dehiscence of 

 the sporocarp ; this follows from the circumstance that the lobes 

 on contracting overlap each other, so that they no longer occupy 

 the same plane, but are deflected somewhat from the central 

 line ; thus one lobe presses in one direction on one side, and the 

 other lobe in the opposite direction on the other side, imparting 

 to the central organs a sort of twist, which tends to cause a 

 rupture at the weakest part of the structure, which in the case 

 under consideration is usually at the junction of the stem and 

 peridium, where, as I pointed out (ante, p. 230), there is a 

 "hilum." Exceptional examples are met with in which the 

 lobes have contracted before the sporocarp has developed suffi- 

 ciently to receive the pressure on what may be termed its " equa- 

 torial"* region. In these cases the lobes are found pressing the 

 sporocarp down to the bottom of the notch formed by the lobes, 

 where it may be seen firmly clasped in their embrace. Why the 

 very similar fungus of rajjfe and others do not exhibit the like 

 phenomena is difficult to explain ; for some unknown reason it 

 seems that the function performed by the contracting lobes is not 

 required in such species. 



No reference has hitherto been made to the sexual organs 

 which must necessarily have existed prior to the development of 

 the fungus. I acknowledge that I have not even sought for these 

 objects, believing that both my optical and manipulative powers 

 would prove insufficient for a successful investigation ; but 

 certain structures that are probably of this nature have been 

 described by others. A German biologist, whose name even is 

 unknown to me, has described and figured in a German scientific 

 journal what he calls "mother-cells"; he discovered them 

 between the membranes of the wing. An eminent entomologist, 

 in describing these bodies to us, sketched a rough section of a 

 wing, and then proceeded to represent the "mother-cells." I 

 noticed he gave a spiral twist to his figures. " Are those glands 



- This is hardly the right term to use ; what it was intended to convey 

 was, that the pressure being apphed in opposite directions on either side of 

 an imaginary vertical axis caused a partial rotation or "twist" of the central 

 organs. — J. C. R. 



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