g BOTANY 



evolution of heat. While respiration is usually more active in 

 animals than in plants, it differs in no other respect in the two 

 kingdoms, and sometimes respiration is active enough in plants 

 to show a very marked rise in temperature. Thus the heat in a 

 hot-bed is the result of the active respiration of the Bacteria in the 

 manure, and germinating seeds respire actively enough to produce 

 a very evident rise of temperature. So, also, large inflorescences, 

 especially when enclosed as they are in many Araceae and Palms, 

 show a marked evolution of heat while the pollen is being shed. 



The popular error that in respiration plants inhale C0 2 and exhale 

 oxygen, is based upon a misconception of what respiration really is. 

 Respiration is here confounded with the assimilation of C0 2 by 

 green plants, or photo-synthesis, a process entirely different from 

 real respiration, which goes on in green plants, as well as in others, 

 quite independently of light. 



Movements in Plants. While movements are usually less pro- 

 nounced in plants than in animals, still no plants are entirely desti- 

 tute of some power of movement. As long as there is living 

 protoplasm in the cells, this must retain the power of movement; 

 and movements of the plant, as a whole, or of special organs, are 

 familiar phenomena even among the most specialized plants. Loco- 

 motion is confined to the simpler forms of plant-life which are not 

 fixed. These low organisms, like Volvox, may be ciliated, and swim 

 rapidly in the water, or the movement may be a slow, creeping one, 

 such as many Diatoms and Desmids show, or a few filamentous 

 plants like Oscillaria and Nostoc. Free-swimming reproductive 

 cells are common in a great many of the lower plants, and this 

 power is retained by the spermatozoids of the Ferns and Cycads. 

 The movements of the growing parts of the higher plants, and such 

 periodic movements as the opening or closing of flowers, sleep-move- 

 ments of leaves, etc., illustrate some of these movements. 



Reproduction 



All living things are capable of reproduction in some form, and 

 in this respect differ from non-living bodies. Plants and animals 

 agree very closely in their reproduction, and we find much the same 

 development of this power in both great groups of organisms. The 

 simplest form of reproduction is the division of an individual into 

 two similar ones by fission. This is very common in a large number 

 of the lower animals and plants. Such reproduction is, of course, 

 strictly non-sexual, and we cannot speak of special reproductive 

 cells as distinguished from purely vegetive (or somatic) ones. 



Non-sexual reproduction occurs in various forms in all plants, 

 while among animals it is rare except in the lower types. In many 



