1886.] 



MICROSCOPICAL JOURNAL. 



105 



the surface of the hypothalline stra- 

 tum the presence of a number of 

 small, variously colored glomerules, 

 with which it is moi'e or less sprin- 

 kled. These are formed at an early 

 stage of the evolution of the hypo- 

 thallus, at or towai'ds its centre, and 

 in immediate proximity to where the 

 spore first germinated. On anatom- 

 ical dissection, it is found that these 

 glomerules consist of minute cellu- 

 lose granules, in the cellules of which 

 are to be seen the gonidia in various 

 stages of evolution. From the fact 

 of their thus occurring in the growing 

 condition, and the impossibility of 

 their entering from without through 

 the closed walls of the cellules, it 

 is evident that the gonidia originate 

 m the glomerules themselves, and are 

 thus, consequently, self-developed or- 

 gans of the lichen. 



' The glomerules gradually become 

 more nuinerous and contiguous as 

 the process of development goes on, 

 until at length a continuous cortical 

 stratum is formed upon the hypo- 

 thallus.' This element is the third 

 added to the structure of the thallus, 

 yet it has been either ignored or mis- 

 interpreted bv the adherents of the 

 algo-fungal hvpothesis. The inter- 

 cellular origin of the gonidia is thus 

 made plain, but it will be inquired 

 how does it happen that in the ma- 

 ture plant the gonidia occupy the 

 centre of the thallus in a seemingly 

 free state.'' It, however, admits of a 

 ready explanation. '■The cortical 

 stratum,' as observed by Nylander, 

 'gradually increasing and expanding, 

 is at the same time, in like propor- 

 tion, dissolved (or resorbed, as it is 

 termed in physiology), beneath, and 

 the gonidia consequently become 

 free.' The gonidia are thus seen to 

 occupv a position between the two 

 cortical strata, and to have been 

 formed after or contemporaneously 

 with them. 



Another and important point 

 claimed by vSchwendener and his 

 adherents must be explained, viz : — 

 The contact said to have been ob- 



served between the gonidia and the 

 hyphae. This contact, says Crombie, 

 is in no way genetic or parasitic, nor 

 does it ai-gue any kind of ' copula- 

 tion.' as has been claimed. The 

 gonidia are neither adnate to nor pen- 

 etrated by the hyphas, but only ad- 

 herent to them by the lichenin, with 

 which all parts of the thallus are 

 penetrated. In all such cases the 

 apparent union is simply an amyla- 

 ceous adherence, and the fancied 

 penetration the result of erroneous 

 observation. 



From these considerations, and 

 others of minor importance might 

 readily be added, it seems that we 

 shall still have our lichens left, for in 

 spite of the many and labored argu- 

 ments which have been advanced to 

 deprive them of their autonomy, they 

 still remain a distinct class, recognized 

 by botanists, between the algai on one 

 hand and the fungi on the other. The 

 line of demarcation which separates 

 them from these orders is no doubt in- 

 distinct, but it is not less so than that 

 separating many other orders of plants 

 or animals, and moreover nature's 

 lines are never rigid. Many debat- 

 able organisms, for instance, on the 

 border-line between the animal and 

 \'egetable kingdoms have been alter- 

 nately captured and recaptured by 

 botanists and zoologists, but with in- 

 creasing knowledge they have now 

 been relegated to one or the other to 

 the satisfaction of all. So with in- 

 crease of understanding we may hope 

 sometime to be able to explain, in the 

 vegetable kingdom, phenomena 

 which now require an element of 

 mystery for their interpretation. 

 o 



On the Collection and Method of 

 Studying Foraminifera.* 



BY J. M. FLINT, SURG. U. S. N. 



I have taken occasion to bring be- 

 fore the society for the inspection of 

 those who may be interested either bi- 

 ologically, geologically, or aestheti- 



*Rt:ad before the Biological Society of Washinglor. 

 Dec. 12, 1885. 



