Urocystis, and had sent some specimens to Farlow with the appended name Uro 

 cystis cepulae (cepulae means of the little onion). Farlow adopted Frost's name and 

 published a description but indicated Frost as the author of the species (althou');h 

 the latter apparently never made a description). Some of the European writers 

 (e.g. Cornu and Franlc) quote Farlow as the author. It is usually referred to as 

 Urocystis cejndae Frost. 



Shortly after Farlow described this as a new species there was considerable dis- 

 cussion among students of fungi as to whether this really was a new species or 

 whether it was identical with some previously described smut. No smut fungus 

 had been described previously from the cultivated onions but some had been 

 described from wild species of the same genus and from closely related genera of the 

 Lihaceae. Thus Urocystis magica was described from Italy on Allium magicum. 

 Farlow, in his second paper (15:114) expresses the opinion that U. cepulae is identical 

 with U. magica Pass. Another closely related smut is U. Colchici Schlecht which 

 occurs on Allium rotundum and a number of species of the Liliaceae outside the 

 genus Alhum. Farlow pointed out the differences between U. Colchici and U. 

 cepulae and considered them as distinct. Cooke (9:634) however, considers the 

 difference insufficient for specific rank and calls the onion fungus U. Colchici var. 

 cepulae. Magnus (28:348) also considered U. cepulae as distinct from U. Colchici. 

 Scliroeter and Winter (Die Pilze, p. 121, 1884) would unite all the above species 

 under U. Colchici. Magnus and Cornu agree with Farlow in keeping the two dis- 

 tinct. Chnton in his monograph of the North American Ustilagineae (8:451) says, 

 "There has been some discussion whether the American species is distinct from 

 Urocystis Colchici and Urocystis mcigica of Europe, the latter species also occurring 

 on species of AUium. The three while very closely related are distinct. The 

 species described here {U. cepulae) differs from both in having smaller spores and 

 spore balls and also from U. Colchici by rarely having more than one spore in a ball." 

 Another species of Urocystis on Allium is U. Allii (Belham) Schellenberg on Allium 

 svhhirsutum. The writers have not examined this species, but both Liro and 

 ScheUenburg regard it as distinct from U. cepulae. Inoculation experiments by 

 Anderson showed A. subhirsutum to be one of the few species of Allium which are 

 immune to U. cepxdae. 



Liro (27) has recently merged the genus Urocystis with the older genus Tubur- 

 cinia because he was unable to distinguish any morphological differences between 

 them and has proposed the name Tuhurcinia cepulae (Fr.) Liro as the correct name 

 for the onion pathogene. This change has been adopted by European writers but 

 as yet has not appeared in American literature. In both of these genera, the spore 

 — more commonly called the "spore ball" — is not a single cell but is composed of a 

 globose ball of a number of cells permanently bound together. In Tuburcinia all of 

 these cells are fertile, i.e. capable of germination, while in Urocystis only the central 

 ones are fertile while the peripheral ones are sterile and called accessory cells. In 

 opposition to this usual conception Liro maintains that no such distinction exists, 

 but that in all these species there is a covering layer of sterile cells. When Fries 

 erected the genus Tuburcinia, the first species which he placed under it was T. Oro- 

 banches, the spore baU of which is composed of 1-3 larger central cells surrounded by 

 a compact layer of smaller, flatter cells. Contrary to the opinion of most previous 

 students of this genus, Liro considers the smaller outer cells as the sterile accessory 

 cells and therefore, that this spore ball differs from that of ordinary species of Uro- 

 cystis in no way. From examination of slides of Fries' original specimen kindly 

 furnished by Dr. Liro, the writers were able to confirm Liro's conclusions in regard 

 to the relative size of the cells ; but it should be kept in mind that the separation of 

 the genera is not based on differences in size of central and peripheral ceUs but on 

 their ability to germinate. Microscopic examination of these slides did not disclose 

 any difference in the outer cells which would prevent germination. Brefeld (Unter- 

 such. A.D. Gesammtg. d. Myk. Heft. 12:180 and PL XL 1895) has published excel- 

 lent figures of the germination of the spores of Tuburcinia primulicola, a species very 

 similar to T.Oroba7icIies,eLiid he shows the peripheral cells germinating in large num- 

 bers. He was unable to find any sterile cells outside of those wliich germinated. 

 Liro does not mention any germination studies and there is no record in the Utera- 

 ture that the germination of the spores of T. Orobanches has been observed. Until 

 the germination of these spores has been studied, and until there is some concord of 



