58 LINDSAY, ON A BROTH ALL US. 



tlioiigh bearing a close resemblance, to the naked eje, are 

 generally more superficial, and tlieir microscopic structure is 

 quite different. I have, on several occasions, mistaken, by 

 the naked eye, small, black, point-like parasitic fungi for the 

 apothecia both of ^. Smithii and A. oxysporus, among v/hich 

 they were interspersed ; most frequently for the latter. I have 

 also sometimes found them growing on these apothecia, — as in 

 specimens from Glen Dee, Braemar, where they inhabit those 

 of A. Smithii. They are generally, however, much more 

 irregular in shape, being usually more or less rough, tuber- 

 culated, and flattened. On microscopical examination, they 

 are found to consist of a cellular envelope of a more or less 

 deep brown tint, enclosing myriads of very minute, globular 

 brown spores. I have already stated that the apothecia of 

 A. oxysporus may be saccate. On the other hand, they are 

 sometimes so prominent and convex, — as in specimens from 

 Loch Coruisk, Skye, that I have mistaken them for young 

 deplanate apothecia of A. Smithii. 



The thecffi, says Tidasne, " subito deorsum acutatss et cunei- 

 formes factae." This is, however, only one phase of tlieir 

 existence, due to distension of the spore-sac and tlieca, with 

 the maturescent spores, — the lower part, or pedicle, as I have 

 already explained, sometimes tapering suddenly from the 

 upj)er, which bulges into a sphere or obovate vesicle. The 

 theca consists, the same observer continues, of a " membrana 

 qua struuntur, crassissima et achroa, quum iode soluto roratur 

 statim tota amoene spisseque cperulescit,talique modo tincta diu 

 (scil. 20 horas et quod excedit) consistit." In regard to the 

 amyloid reaction Avith iodine, the thecae of this species contrast 

 strongly with those of A. Smithii. I uniformly obtained a 

 blue colour, which was generally best marked in young theese, 

 and at the apex, where the membrane is thickest. In some 

 cases the hypothecial tissue, and, in others, the intercellular 

 substance, which glues together the tips of the paraphyses, 

 appeared to strike a blue colour with iodine, especially during- 

 the young state of the thecfc. Tulasne refers to this circum- 

 stance in regard to the paraphyses : " Materie amorpha 

 cujus ope adglutinari videntur abundat ca?ruleoque colore 

 in iode confestim inficitur.^' I am not certain, notwith- 

 standing, that this amyloid matter does not really pertain to 

 the thecse. The tips of the paraphyses are of a much lighter 

 brown than those of A. Smithii ; the colouring matter appears 

 here also more diffused. Their apices are so closely united, 

 that it is generally impossible, without the assistance of 

 reagents, to discover the outlines or characters of the indivi- 

 dual terminal cells. But aqua potassse at once causes their 



