252 



PLANT LIFE. 



rise to a i)lant of the other or sexual phase ; the sporophyte 

 produces the gauietophyte. (For a description of the plant 

 thus formed see f 385.) 



353. Perianth. — The perianth is not present in any 



Fig. 272. — A^ hanging flower of milkweed, seen from the side. Tire petals are sharply 

 reflexed. Natural size, i?, the upper part of same, magnified about 2j diam., with 

 two of the appendages, a, of the stamens cut off and the front of the anther wall dis- 

 sected away to sho\V its two pollen masses. C, two pollen masses from neighboring 

 anthers connected to a clip, by which they may be attached to the foot of an insect. 

 Magnified about 8 diaiu. />, foot of an insect with pollen masses attached. In Cand 

 D the pollen masses are inverted as compared with their position in A and B. — After 

 Kerner. 



gymnospernis {*{\ 2,^2>)^ e.xcept in a rndimentary Ibrni in a 

 few species of the highest order. In angiosjierins the 

 perianth, which is rarely wanting, is primarily for the 

 protection of the sporophylls. As in all cases where leaves 

 are produced ra[)idl)' and in close jiroxiniity on a short 

 axis, they grow during tlieir early stages more rapidly 

 npon the outer face than tlie inner. They are, therefore, 

 concave inward and closely pressed together, fornn'ng a bud. 

 At a certain stage the growth npon the two faces of the 



