MICOGRAPHIC STUDY OF SAFFRON DISEASE. 



25 



1 have shown above that Fougeroux compared the Tacon to 

 bunt in wheat, but in this particular he is clearly wrong. The 

 tissues affected belong to very different organs, and have nothing 

 in common except inclosing in their cells amylaceous matter. 

 The labours of the Messrs. Tulasne have shown that the nior- 

 phosis of bunt (Tilletia Caries) is different from that of smut 

 (Ustilago), though at maturity it is scarcely possible to dis- 

 tinguish generically the species of these two genera. The 

 progress of the malady and its consequences are therefore quite 

 different in the two plants. 



As to the means of arresting the propagation of the Tacon, 

 or to prevent its reproduction the following year, in the absence 

 of any observations of my own, I must again have recourse to 

 the Memoir of M. Fougeroux. He informs us that the most 

 approved remedy is immersing the bulbs in an alkaline solution, 

 as in thick lime-water, &c, in which they are to be steeped for 

 two hours. He proposes also leaving them some days in 

 wine-lees. 



Fougeroux informs us, moreover, that the Rhizoctonia may 

 exist at the same time on the saffron bulb as the Tacon. 



I have said above that the coat of the bulb, blackened by the 

 progress of the disease, retains for a long time its original form. 

 On this a species of Perisporium is frequently developed which 

 I have called P. crocophilum, Mont. It is characterised : 

 "Peridiis minimis ovoideo-globosis atro-nitentibus apice poro 

 pertusis e basi fibras irradiantes emittentibus ; nucleo primitus 

 celluloso, cellulis subconcatenatis, sporis globosis minimis." 



M. J. B. 



I take the opportunity of adding to this memoir a few words 

 on some bulbs of Tulips which were attacked by Sclerotium 

 Cepce, Lib., and Sporotrichum polysporum, Link. I have laid 

 before the Society of Biology an account of a disease very pre- 

 valent in tulip-roots sent me by M. Rayer. I have clearly esta- 

 blished the fact that it is due to parasitic fungi. In some between 

 the scales of the bulb I found a large number of globular grains, 

 black and shining when fresh, and of the size of a grain of hemp. 

 These parasitical bodies, already observed by Madame Libert in 

 Belgium, and in England by Mr. Berkeley, upon bulbs, whose 

 further development they had prevented, have been referred to 

 Sclerotium by these two cryptogamists. Other bulbs presented 

 as the cause of evil a very different parasite from the first. The 

 roots and the base of the scales were deformed by bundles of 

 white threads, which, examined under the microscope, belonged 

 certainly either to Sporotrichum polysporum, Lk., or to some 

 very nearly allied species. 



