116 M. L. R. Tulasne on the Reproductive Organs 



of these corpuscles (which might be called spermatid) precedes 

 that of the spore-bearing cells, for the young apothecia are 

 densely filled with the first before the second have acquired a re- 

 cognizable form. On the dissociated thallus of V. epidermidis,. 

 seminiferous perithecia and other smaller conceptacles contain- 

 ing only the linear corpuscles or spermatia occur scattered and 

 intermingled, and it is impossible to avoid regarding those two 

 kinds of perithecia as belonging to one and the same plant. 



An examination, both of other crustaceous Lichens (e. gr. Ur- 

 ceolaria scruposa, cinerea, Lecanora atra, circinata, Placodium 

 murorum, radiosum, Squamaria lentigera, &c.) and of foliaceous 

 Lichens (e. g. Parmelia tiliacea, aipolia, Acetabulum, Gyrophora 

 hirsuta, pustulata, Loboria pulmonacea, Sticta glomulifera, lier- 

 hacea, &c.), will in like manner show that the Itzigsohnian cor- 

 puscles or spermogoni which occur in them must belong to them ; 

 and it is impossible to doubt that they are peculiar organs of 

 these plants, unfairly neglected by lichenographers hitherto. This 

 opinion may be expressed with the more assurance since it is by 

 no means the case, as M. von Flotow imagines, that these organs 

 occur only on certain Lichens, for they are found upon so great 

 a number that the list of the species which appear to be devoid 

 of them is probably very limited. 



On the other hand, the extreme dissimilarity of form and size 

 existing between the spermatia and true spores, the constancy of 

 these difierences, and above all, the mode of generation peculiar 

 to each of these organs, render the idea that the spermatian cor- 

 puscles are imperfect or young spores, altogether improbable. If 

 this be so, neither perhaps does their extreme tenuity allow us to 

 suppose that they are organs of fissiparous or gongylary repro- 

 duction, the Lichens being moreover furnished very abundantly 

 with organs of this nature in their gonidia and the gemmae of 

 various forms of which these are the principal elements. Thus 

 these reflections tend to increase the probability of the opinion 

 which regards, with M. Itzigsohn, the brown points observed by 

 him as organs of the male sex in the Lichens. But it must not 

 be concealed that their little analogy, in regard to structure, with 

 the antheridia of the Algse and Muscinese, is unfavourable to 

 their assimilation with these organs. So that just as the nature 

 and true functions of the latter seem destined to be for a long 

 time more or less problematical and questionable, this will doubt- 

 less also be the fate of the spermogoni in the history of the 

 Lichens. At the same time it is doubtful whether their dissi- 

 milarity from the antheridia already known is a sufficient reason 

 for denying the function attributed to them ; for, if among those 

 there are some which are similar, as the antheridia of the Mosses 

 to those of the Ferns, others, such as the antheridia of the Algjs 



