or piLOBOLus. 165 



they are elliptical, of a pale straw-colour, and without any evident 

 external membrane until treated with aether or alcohol, when by 

 the contraction of the contents such membrane becomes visible, 

 not however in the form of a broad dark band, but of a clear and 

 bright line. The contents moreover are very slightly, if at all, 

 granular. 



In Bolton's account of Filobolus roridus no particulars are 

 given of the spores — indeed the microscopes of his time would 

 hardly have enabled him to do so with accuracy ; in other respects 

 his account agrees sufficiently with the above description to lead 

 me to think that his Filobolus roridus is the same as that which 

 I have described. There are two very curious facts connected with 

 the above Filobolus, which I have had an opportunity of investi- 

 gating, and which are worthy of notice. They are alluded to by 

 Dr. Cohn as having been noticed by former observers in Filo- 

 bolus crystallinus, but he refrains from giving any opinion, inas- 

 much as the appearances in question had not fallen under his 

 own observation. The first is mentioned by Muller, the original 

 discoverer of Filobolus crystallinus, who states that he had seen in 

 many of the vesicles a small white delicate worm, which crawled 

 round and round, and appeared to swim as it were in a little 

 ocean of its own. Muller thereupon came to the conclusion that 

 Filobolus crystallinus was neither animal nor vegetable, but a 

 mixture of the two, in fact a Zoophyte — not in the modern accep- 

 tation of that term, but according to its proper meaning. Persoon, 

 on the other hand, alleged that these creatures were nothing but 

 Anguillulce, which came out of the dung and crawled on the outside 

 of the fungus. It would seem that Persoon' s opinion is correct, 

 for I have several times observed a species of Anguillula encased 

 in the drops of water on the surface of my Filobolus, and twirling 

 round so actively that it is a matter of surprise that it does not 

 cause the drops to collapse. There is no difficulty in extracting 

 the worm from the drop, and it appears to be the common An- 

 guillula fluviatilis, which no doubt climbs up the stem of the 

 fungus and deposits itself in one of the numerous dew-drops. 

 Similar worms may be seen crawling on the surface of the dung 

 and unconnected with the fungus, leaving no doubt as to their 

 place of origin. The sight of these animals revolving rapidly in 

 their crystal cases is most curious and interesting. It is no matter 

 of surprise that Muller should have been led to suppose that 

 the worm was in the interior of the plant, for it not unfrequently 

 happens that before the real vesicle is formed, a drop of water 



