. Lessons with plants. Suggestions for seeing and interpreting some of the common forms of vegetation. s.^ 4236. Correlative or correlated characters are concomitants ofthe main or type characters. They are incidental features, whichhave been carried along by the main line of ascent, and whichare of little significance to the present well-being of the organism. 423c. The genealogy of an organism is called its life-history of a single or individual organism is its is, phylogeny is the natural history of the race, whereasontogeny is the natural history of a single ind
. Lessons with plants. Suggestions for seeing and interpreting some of the common forms of vegetation. s.^ 4236. Correlative or correlated characters are concomitants ofthe main or type characters. They are incidental features, whichhave been carried along by the main line of ascent, and whichare of little significance to the present well-being of the organism. 423c. The genealogy of an organism is called its life-history of a single or individual organism is its is, phylogeny is the natural history of the race, whereasontogeny is the natural history of a single individual. Phylogeneticcharacters, therefore, are those which have come down from theancestry; ontogenetic characters are those whic{f have originatedwithin the life-time of a given individual. i2Zd. An acquired character is an ontogenetic character whichis obviously the result of some environmental circumstance, as ofsoil, light, or temperature. Suggestion.—Let the teacher assign one kind of plant to eachpupil, asking him to discover how the seeds are dispersed. 342 LUSSOAS WITB PLANTS LXVI FERNS. Fig. 357. Fruiting pinnules of maiden-hair fern. 424. Maidenhair ferns are frequent in woods,and are common in cultivation. The leaves of large or mature plants often have a stiffish and angular look, and if such leaves are examined it will be found that the edges are turned under (as in Fig. 357). If these flaps are raised, many minute brownish bodies will be discovered, adhering to their surface. These bodies, which are called sporangia or spore-cases, contain numerous spores, which are barely visible to the naked eye ; and these spores germinate and produce new plants. 424a. Tiie leaf-blade of a fern is known as a frond, a termwhich is also applied to the leaf-like bodies of duekmeats (252)and 1o the leaf-like parts of certain other plants, where there islittle distinction of ribs or veins and no well-differentiated stem of tha> frond is called a stipe. 425. A bit of
Size: 1670px × 1496px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbai, bookcentury1900, bookdecade1900, booksubjectbotany
