564 Microscopic Organisms in Blood and their Relation to Disease. \ykKY iii. 



branched, segmented or unsegmented filaments ; (2) Sjprouting-fiingi, yeast cells of 

 various kinds, consisting of more or less oval corpuscles which multiply by means of 

 sprouts from their surfaces ; and (3) Gleft-fitngi or Schizomycetes — minute spherical 

 or oval bodies which are multiplied by fission only, and which sometimes remain isolated, 

 at others form unbranched rows (rods, threads, etc.), but only occasionally present a 

 cubiform aspect. To this group the bacterium, vibrio, vibrio-bacillus, spirillum, etc., 

 belong. , 



Nageli writes : " I have separated the lower forms of fungi into three groups. On 

 account of many practical questions it is of importance to know whether specific 

 dififerences really exist, or whether we have to do with the same species under different 

 conditions, it being possible that different fungi possessed a ' mould,' a ' sprout,' or 

 a 'cleft' form. This is a subject which has formed the subject of debate during the 

 last sixteen years, and many observations have been recorded for the purpose of showing 

 that, as a result of cultivation-experiments, the most opposite forms have been seen 

 to pass from one into the other." With reference to this point Nageli forcibly points 

 out the fallacies to which men are liable in drawing conclusions from cultivation- 

 experiments, and says that, in many respects, it would be as rational for the husbandman 

 to assert that the weeds in his field were the result of transformation which the seed 

 of wheat previously sown had undergone. No one would believe such a statement, 

 for the seeds of weeds are large enough to be easily recognised, whereas the germs of 

 fungi are of microscopic dimensions — those of the schizom^ycetes often barely distin- 

 guishable with the highest powers : hence the assertions which have been made regarding 

 the transition of such minute organisms cannot easily be controlled. " Moreover," adds 

 Nageli, " the rapid and superficial observer has a marked advantage : the conclusions 

 which he has arrived at as the result of a so-called uncontaminated cultivation 

 [Meinkultur'] of a single week's duration may require years of labour on the part of 

 the thoroughly competent observer to disprove." 



This question has of late years been investigated by many distinguished savants, 

 notably by Professor de Bary of Strasburg. He has shown that a fungus undergoes but a 

 ~ very limited and well-defined range of changes. Nageli, as the result of his own ob- 

 servations, declares that, of the three groups of fungi above referred to, the " mould " 

 and "sprout" fungi are closely related, but that, with one exception, they have not yet 

 been seen to pass from one form into the other. The exception consists in the circum- 

 stance that a certain species of mucor (a mould) has been observed to present the two 

 forms of vegetation— the filamentous and the sprouting. Fission-fungi, however, do 

 not stand in any genetic relation to either of the other two groups, for they neither 

 give rise to other fungal forms nor originate from them : hence it is distinctly laid down 

 that they do not germinate. In this it would appear that Nageli and de Bary are 

 completely in accord. Nageli states that it is comparatively easy to demonstrate that 

 the " fission " group of fungi are not transformed into other groups from the circumstance 

 that members of the latter when present in a solution are killed at a lower temperature 



