134 FERN GROWING 



development takes place before the birth of offspring. In 

 birds, eggs are laid, and the mother keeps them warm until 

 they hatch. The toad deposits eggs in water, these develop 

 into tadpoles, and after a time become young toads. The 

 butterfly brings forth eggs, from which caterpillars issue, 

 change to the chrysalis state, and afterwards emerge as fully 

 grown butterflies. Fish deposit a mass of ova, which are 

 afterwards fertilised. The slug is hermaphrodite, each pair of 

 individuals laying eggs. Bees are male, female, and workers ; 

 and passing down to near the bottom of the scale, we have 

 amongst protozoa, &c., a simple reproduction by the breaking 

 of the individual into fragments. 



In plants, flowers are formed, having male and female 

 organs (stamen and pistil), which eventually produce seeds. 

 These flowers may be dioecious, i.e., unisexual flowers of the 

 same species produced on distinct individuals, as in the yew 

 (where we have male and female trees) ; if monoecious, the two 

 kinds of unisexual flowers are on the same plant, as in the 

 cucumber I but there are a vast number of the species in various 

 genera that are hermaphrodite, where the stamens and pistils 

 are present within the same perianth, as in the cowslip. 

 Descending in the scale, we have Ferns forming spores on the 

 fronds, which germinate into prothalloid life, having the organs 

 of generation that reproduce the frond life showing a double 

 existence. It is not therefore difficult to conceive that we 

 have here a distinct arrangement of hermaphrodite reproduction, 

 or the spore growth (prothallus) having a number of archegonia 

 (female cells), each containing a central cell (oosphere), and a 

 number of antheridia (male cells) filled with spermatozoids. 

 Why should not more than one of these archegonia attract 

 swarms of spermatozoids, and, all being on the same pro- 

 thallus, why may not this effect be diffused through the 

 whole prothallus by assimilation, and thus cause multiple 

 parentage ? 



