64 HENRY S. CONARD 



we had not something simpler, truer, and equally convenient. 

 It is to be desired that beginning students shall approach their 

 studies with clear, concise and accurate ideas of a permanent 

 classification. This demands dropping a scheme which places 

 ferns and seedplants in sharply separated primary divisions of the 

 Plant Kingdom. So much for omissions. 



The designation of Thallophyta and Embryophyta as the 

 primary divisions of the Plant Kingdom is not all that could 

 be desired. The lower group is far from homogeneous, and is 

 characterized more by lack of definite organization than by any 

 positive element. It is only in a distant way to be considered 

 monophyletic. Engler's arrangement of these plants under 

 eleven coordinate headings certainly has much to commend it; 

 it is, however, too cumbrous. The gathering of these together 

 under the single title Thallophyta does no violence to the facts. 

 The larger unit is so convenient as to be almost indispensable in 

 elementary work. At any rate it has found very wide accept- 

 ance and may well be retained. Under this heading the system 

 of Engler's Syllabus, or Oltmann's Algae, or Lotsy's Lectures 

 may be readily used. As to phylogeny, the family tree of the 

 Vegetable Kingdom, when satisfactorily completed, will most 

 resemble the classic hour-glass-shaped pasture-form of thorn 

 tree — from a broad bushy base, representing the lower plants, 

 will arise a fairly clean cut trunk, which again branches above 

 into the broad and bushy crown of the Embryophyta. The 

 unity of this latter group is attested by the widely accepted name 

 of Archegoniatae. We have preferred the newer name for three 

 reasons. First the occurrence of an embryo developed from the 

 fertilized egg and cared for during its early stages within parental 

 tissues, is an outstanding character of the group, and it is this 

 character which has probably been a determining factor in the 

 survival and extension of the group. The statement in Gray's 

 Manual, p. 33, that ferns are without embryo refers only to the 

 product of the spore. Secondly, the archegonium is at best a 

 small and obscure organ, not easily seen or appreciated; and it 

 is completely obliterated in the higher members of the series. 

 Finally, according to the euphony (or terminology, if you like) 



