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Evolution in the Plant Kingdom. 325 
remains in doubt. At any rate, they probably have a far greater 
complexity than was formerly supposed. We have thus come to 
consider protococcoid forms as our foundation-stones in rearing the 
structure of the plant kingdom. Through all the Thallophytes 
{representing the four lowest of our seven primary groups) there 
run two parallel lines, the typical or normal plants, containing chlo- 
rophyll; and the degraded plants, which are destitute of chloro- 
phyll. This distinction is a very deep-seated one in the plant 
kingdom, for chlorophyll-bearing plants alone can do normal plant 
work, viz., the conversion of inorganic to organic material through 
the agency of chlorophyll and sunlight. Plants without chloro- 
phyll must live as parasites or saphrophytes, a degraded habit 
which leads to degraded structure. The former in the first four 
groups, are called Algæ, the latter Fungi. The general opinion, 
brought out clearly in the address of Dr. Farlow, already referred 
to, is that Fungi are degraded representatives of Algæ—relatives 
in reduced circumstances, whose lazy habits of parasitism have 
entailed upon them degenerate bodies. Just what Fungi have 
descended from what Alge it is perhaps impossible to say. The 
chances are that some of our important Fungi are degraded rep- 
resentatives of algal forms which no longer exist. Specific state- 
ment with regard to this relationship is little better than guess- 
ing; but the general proposition seems to be fairly well 
established. We have advanced, then, thus far: that of the two 
parallel lines, Algæ and Fungi, which run through the four lowest 
plant groups, the plant kingdom is to be considered as having 
advanced in the line of the Algæ, the chlorophyll-bearing line; 
while the Fungi are simply so many degraded forms, which lie 
strewn along this line of general progress, like drift wood stranded 
along the banks of a stream. For our purpose, then, the Fungi 
are to be dismissed, their probable origin having been sufficiently 
indicated. Starting, then, with protococcoid forms, advancing 
along the lines of Algæ, and into the chlorophyll-bearing members 
of the groups above, what notions of evolution can be obtained? 
Examining our present schemes of classification it will be discov- 
ered that chief stress is laid upon the methods of sexual repro- 
duction. It is, as yet, the best thread upon which our facts can 
se strung, and it usually expresses so thoroughly the highest effort 
on the part of the plant, that as it advances from simplicity to 
