IK^TSOX. — CULTUUK STl'DIKS OF FUNGI. 299 



bulbils of Papuluspora sporotrkhoides. Thoir (Ifvelopinent, however, 

 is clearly that of compound spores and not of bulbils. 



Elcomyces old Kirchner ('88) a fungus found growing in popp> oil, 

 produces a compound spore which consists at maturity of a large 

 thick-walled functional cell, surrounded by several empty coherent 

 cells, the whole resembling the bulbil of Acrospeira. If, as suggested 

 by Kirchner, this body results from the coherence of several adjacent 

 cells, it might well be regarded as a bulbil and not a compound spore. 



\'arious other spore-forms might be mentioned whicli bear more or 

 less resemblance to bulbils, but those almve enumerat(Ml are sufficient 

 for purposes of illustration. Before leaving bulbil-like forms, liow- 

 ever, tAvo or three additional types may be mentioned, the nature of 

 which is not altogether clear, since they are neither compound spores 

 nor typical sclerotia. 



Acgcrita JVcbben Fawcett ('10), a fungus attacking scales on Citrus, 

 produces, under certain conditions, bulbil-like bodies which consist of 

 loosely coherent spore-masses closely comparable to those of the 

 aberrant Papidospora polyspora, the development of which, under 

 moist conditions, has been described above. 



Sorosporclla Agrotidis Sorokin ('88, '89), which attacks the larvae 

 of Agrotis, fills the latter with loosely but definitely coherent cell- 

 groups which miglit also be compared to those of P. poh/spora. 



Lastly, among structures which bear a striking resemblance to bul- 

 bils, the peculiar spore-balls of Spongospora subtcrranca (Wallr.) 

 Johnson should be mentioned; which, although they might readily be 

 taken for a species of Papulospora, have been shown to belong to the 

 life-cycle of one of the Mycetozoa. 



THE MORPHOLOGICAL SIGNIFICANCE OF BULBILS. 



Opinions concerning the morphological significance of bulbils differ 

 widely. Preuss ('51), Eidam ('83), DeBary ('86), IVIattirolo ('86) 

 all regarded them as normal structures which function as auxiliary 

 methods of reproduction; while Karsten ('65), Zukal ('86), ^Nlorini 

 ('88), and Baineir ('07) looked upon them as immature ascogenous 

 fructifications of either perithecial or apothecial forms, believing 

 that their arrested growth was due to unfavoralile environment, and 

 that, with proper nutriment, they might be able to complete their 

 development. 



Although it is possible that the last mentioned view may be correct 

 in some instances, it is quite certain that in many cases, where both 



