60 THE DEVELOPMENT OF RAW COTTON 



The transmission of inherited characters also appears to be 

 centred mainly, if not entirely, in the nucleus of the sex- 

 cells. 



The ovules contain each a large cell in the centre (Fig. 11, 

 A, g, h), in which is a single female or egg-cell, with its nucleus, 

 accompanied by a bevy of seven other nuclei, each with its 

 definite function. Fertilization of the egg-cell by fusion with 

 one of the male nuclei of the pollen-grain (Fig. 11, B, a) 

 produces a fusion nucleus, or fertilized nucleus (Fig. 11, B, 6). 

 The fertilized egg-cell thus formed is the first origination of a 

 new plant, and on looking down the microscope tube at two 

 fusing nuclei, whose aggregate diameter is only 0*015 milli- 

 metre, or one-fifteen-hundredth of an inch, it must be realized 

 that the nature and origin of these two specks of protoplasm 

 is determining irrevocably the nature of the plant which will 

 grow from them (Fig. 11, B). 



Of these various portions of the flower, the first to show 

 itself in the developing bud is the calyx. The rounded end 

 of the branch within the three tiny bracts begins to make a 

 ring-shaped protuberance. Within this ring two other rings 

 are formed, the outer one having an undulating edge, and 

 its five undulations growing into the five petals. The inner 

 ring grows up into a hollow cylinder, and the stamens arise on 

 the outside of this cylinder as isolated protuberances, which 

 develop into the stalked yellow or buff-coloured sacs con- 

 taining the pollen-grains. 



When these latter protuberances are so far advanced that 

 the processes which will result in the formation of the pollen- 

 grains themselves have already begun, a fourth and last set 

 of rings arises on the end of the branch, within the stamina] 

 cylinder. These rings develop into the ovary, and ^thence 

 into the boll. They are variable in number according to the 

 kind of cotton, and are situate around the centre of the enel 

 of the branch. Each one as it grows becomes larger at the 

 base, forming a flask-shaped body (Fig. 11, A, c); the necks 

 of these flasks adhere to one another, and ultimately form 



