36 THE AMERICAN MONTHLY [Fehniary, 



eventually grow out in a radiate manner from the sclerotium as 

 slender, colorless, septate hyphae or sporophores, each producing 

 at its apex a whorl of simple or branched concatenate chains of 

 small, elliptical, olive spores that agree in every particular with 

 the secondary spores borne on the mycelium of the germinating 

 spores (Fig. 12). The spores produced by the sclerotia, when 

 placed on the leaves of the host-plant, produce the Heterospo- 

 rium. 



Fig. 6 represents two sporophores of the Heterosporiuin 

 after remaining in water on a slide for four days ; it will be ob- 

 served that two slender filaments have developed, each bearing a 

 fascicle of change of spores similar to the secondary spores borne 

 on the filament of germinating spores. 



Finally, if leaves infested with the Heterosporium are ex- 

 amined in the autumn, blackisli perithecia will in many instances 

 be found ; these bodies are subglobose, slightly attenuated up- 

 wards, furnished at the apex with a minute aperture, and when 

 mature have the inner surface covered with very short sporo- 

 phores, each bearing at its apex a minute body, resembling in 

 every respect the secondary spores of Heterosporium spores. 

 These minute perithecia originate from mycelium closely re- 

 sembling that of Heterosporium^ but I have not seen any sug- 

 gestion of a resemblance to these bodies in any of my cultures, 

 neither have I succeeded in causing the spores of these structures 

 to germinate ; consequently their relationship or otherwise with 

 Heterosporium is at present unknown ; it is certain, however, 

 that these bodies have no necessary control over the continued 

 development of the Heterosporium. — J. R. M. S. 



Microscopical Technique Applied to Histology. — I. 



(From the Fretick of M. Rene Boneval.) 



[The following chapters are abstracts of M. Rene Boneval's 

 admirable " Nouveau Guide Pratique de Techtiique Micro- 

 scopique appliquee a V Histologie et a V Embryogenie" a 

 work of such excellence and one so well adapted to its purpose 

 (that of instructing the beginner in the preparation of histological 

 material), that the translation is offered to our readers in the hope 

 that at least some will be thereby induced to study the structure 

 of animal tissues, and that those engaged in teaching the novices 

 in histology will find its elementary methods helpful. The for- 

 mula and methods given by M. Boneval are those which he has 

 proved to be trustworthy, and those which any intelligent begin- 

 ner may prepare and use without further aid. The chemicals 

 needed are usually only such as any good drug-store can supply 

 or any dealer in microscopical materials furnish at small cost. 

 It is assumed that the reader is familiar with the use of tlie 



