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Mycologia 



first table mean that 16 lichenists favor maintaining lichens as a 

 natural group while one thinks that the grounds for distribution 

 are stronger though there are reasons for maintaining the group. 

 Figures (10-5 2 ) in the second vertical column of the first hori- 

 zontal row mean that 10 mycologists and pathologists think that 

 lichens should be maintained as a natural group while five think 

 that they are probably a natural group, but should in any event 

 be kept distinct for the sake of convenience in study. The com- 

 bination i a_b in the first horizontal row and the third vertical 

 column means that one morphologist or anatomist thinks that 

 lichens may form a natural group, but that they more probably 

 do not for reasons given under (a) and (b) in the table giving 

 reasons of distributing the lichens. The figures (2-2 1 -! 2 ) in the 

 first vertical column of the first horizontal row of the second 

 table mean that two lichenists believe that lichens should be 

 distributed because not a natural group ; that two others think 

 there are arguments for this view, but that there is stronger argu- 

 ment for the validity of the natural group Lichenes ; and that one 

 other lichenist thinks that lichens are perhaps not a natural group 

 but that they should be kept distinct for the sake of convenience 

 in study. With these explanations it is believed that a study of 

 the two tables will make the figures in the columns intelligible. 

 The total for each horizontal row of figures gives the number of 

 times that the view expressed in that row is favored in the replies ; 

 and the totals for each vertical column of figures indicates the 

 number of times that all the arguments for maintenance or for 

 distribution are favored by all the botanists belonging to the 

 group placed in this vertical column. By way of illustration the 

 opinion that lichens form a natural group is expressed 47 times, 

 and reasons for maintaining these plants as a distinct group are ex- 

 pressed 33 times by lichenists. The vertical and the horizontal 

 grand totals agree of course. The whole number of expressions 

 favoring maintenance (146) is much larger than the number of 

 botanists who stated that they favor distribution, because some 

 of the replies give more than one reason for maintaining the 

 group and because the views of 20 botanists are expressed in two 

 columns for the reason stated above. The figures with exponents 

 are not expressed in the totals and, since the first choices are ex- 



