THE BEGINNINGS OF LIFE. 



567 



MODES OF DEVELOPMENT 



IN RELATION TO 

 ASEXUAL MULTIPLICATION OCCURRING DURING ITS PROGRESS. 



Explanation 

 of signs. 



(a) Signifies internal gemmation. 



(b) Signifies fission or external gemmation. 



(c) Budding, without separation. 



(d) Budding without separation at first, though subsequently 



separation of some or all of segments. 



(e) Reproduction by fertilized germs. 



A. Multiple derivative forms 'alternate generation.' 



i. Distoma germ, (a) 

 ist Brood, (a) 

 2nd Brood, (a) 

 3rd Brood (Cercariae). 



Encysted state. 



Distoma larva. 



Mature Distoma. (e) 



4. Fern germ, (c) 

 Immature Fern, (c) 

 Mature Fern, (b) 



Spores, (c) 



Prothallium. (e) 



7. Aurelia germ. 

 Ciliated Embryo. 

 Polype, (cd) 

 Medusae, (e) 



10. Salpa germ. 



Larva Stock, (dd) 

 Mature Salpse. (e) 

 (aggregated) 



2. Moss germ, (b) 

 Protonema. (d) 

 Protonema. (c) 

 Incipient Moss, (d) 

 Mature Moss, (e) 



5. Myrianida germ, (c) 

 Larva, (cd) 

 Mature Myrianidae. (e) 



8. Sertularia germ. 

 Ciliated Embryo, (c) 

 Polypidom. (d) 

 Capsules, (a) 

 Medusae, (e) 



ir. Flowering Plant germ, (erf) 

 Immature Plant, (c) 

 Mature Plant, (e) 

 (aggregated) 



3. T. echinococcus germ. 

 Active Embryo. 

 Hydated Cyst, (cd) 

 Echinococci. (c) 

 Mature Entozoon. () 

 Proglottides. (e) 



6. T. serrata germ. 

 Active Embryo. 

 Cysticercus. (cc) 

 Mature Entozoon. 

 Proglottides, () 



. (c) 



g. Coryne germ. 

 Ciliated Em 1 - 

 Polypidom. 

 Polypidom. 

 Medusae, (e) 



12. Aphis germ. 



Immature Aphis, (a) 

 Immature Aphis, (a) 



&c. 

 Mature Aphis, (e) 



B. Process intermediate between 'budding' and metamorphosis product of Larva single. 



13. Asterias germ. 

 Bipinnaria. (a) 

 Immature Asterias. 

 Mature Asterias. (e] 



14. Echinus germ. 

 Pluteus. (a) 

 Immature Echinus 

 Mature Echinus, (e) 



C. Complete development of germ stock -with multiplication and metamorphosis. 



Botryllus germ (b) 



Immature Botrylli. ( 



Mature Botrylli. (e) 



(aggregated) 



Ascidian germ. 

 Tadpole-like larva. 

 Fixed Ascidian. (c\ 

 Mature A&cidians. (e) 

 (aggregated) 



17. Bryozoa germ. 

 Ciliated Embryo. 

 Fixed Bryozoan. (c) 

 Mature Bryozoa. 

 (aggregated) 



D. Complete development of germ -with or without multiplication, but with 

 metamorphosis. 



1 8. Hydra germ. 



Immature Hydrae. (d) 

 Mature Hydra, (e) 



19. Eolis germ, (b) 

 Immature Eolis. 

 Matwe Eolis. (< 



21. Vertebrate germ. 

 Asexual Vertebrate. 

 Mature Vertebrate, { 



20. Vertebrate germ. (*) 

 Asexual Vertebrate. 

 Mature Vertebrate, (e) 



* Some of the most typical modes have been selected and stated in the simplest manner, with 

 the view of facilitating comparisons and appreciation of real relationships. 



