XIII. FUNGI. 949 



itself; the other of translation, -which enables it in a short time to tiaverse a somewhat considerable space. 

 To observe these motions the glass plate for the object should be traversed by two grooves crossing at right 

 angles; in each groove a metallic thread should be lirtnly cemented, and these threads leave in ike 

 middle of the glass a free space where the eorpuscales swim ; the induction apparatus is a reel, the 

 generator being a simple ■element of bichromate of potash. All things being thus arranged, it is easy to 

 pass the inductive currents through the prepared liquid between the supporting plate and the film of glass 

 which covers it. The antherozoids of Hepaticee and Mosses are not influenced by the induced currents ; 

 their movements are not modified, and their relative positions remain the same, although they may be in 

 the path of a strong current. But it is different with the spermatia of Lichens and Fungi : the moment 

 that the small imbedded threads on the object-glass are brought into contact with the points of the 

 induction coil, .the thousands of spermatia visible in the field of the microscope place themselves 

 parallel to- the current, i.e. with their longest diameter in a straight line between the points; their 

 movement? of translation are then entirely arrested; their trepidation continues, but feebly. If, by 

 means of the two other threads cemented to the object-glass, the electricity is passed in a perpendicular 

 direction to the first, the spermatia immediately move, and place themselves in this direction. Instead 

 of touching end to end, under the influence of the current, as if they attracted each other, they aiTange 

 themselves parallel to each other and to the current. If the current be weakened by degrees, its influence 

 is no longer felt in the centre of the arrangement ; there the spermatia resume their movements and 

 irregular positions ; whilst towards the two points the action of the current continues to manifest itself, 

 and the arrangement in line continues. If the current be entirely arrested, the corpuscules disperse in 

 every direction ; as soon as it recommences, they again fall into line, and may remain for hours without 

 change. While the induction current is passing, there can be no movement of the liquid, since, there being 

 no progression of the spermatia at each change of direction of the current, they remain motionless in the 

 water which contains them, and only revolve upon themselves. This singular arrangement in line can 

 only arise from a polarization similar to that which is produced by induction in several metallic conductors 

 placed close together. 



XIII. FUNGI, Jussieu, Persoon, &c. 



(HxMBNOMTCETES, Fries. — Discomtoetes, Fries. — Gasteeomtcetes, Fries. — 

 Pteenomtobtes, Fries. — Htphomtoetbs, Link, — Gtmnomtoetes, Link.) 



Cellular Acotyledons, very various in duration and texture, epigeal or hypogeal, 

 generally parasitic on decaying vegetable or animal substances, on the barJc of trees, on 

 the surface or interior of leaves, and even on other Fungi, very rarely living on stones or 

 in water, lovers of shade, always deprived of fronds, stomata and green parts. Oegan 

 OF VEGETATION (mvcelium) mostly subterranean, composed of elongated cells, which are 

 isolated, or form a web or membranes. Oegans op peuotification home on the myce- 

 lium, sesmle or pedicelled, naked, or contained in a peculiar envelope, very various in 

 form, and hearing the spores on the interior or etcterior.^ Spoees, sometimes home upon 

 hashdm, sometimes contairved im, sporangia (thecal , mostly formed of two membranes, 

 always (?) motionless. 



Fungi, together -with Lichens, form a group of Cryptogams possessing no 

 archegonia ; they are polymorphous, [often] ephemeral, annual, or perennial, never 

 green"; composed either of filaments, or of a loose or close tissue, pulpy or fleshy, 

 rarely woody ; sometimes furnished with peculiar vessels containing a white, yellow 

 or orange milky juice. 



They grow above or under ground, on decomposing vegetable or animal matter, 



