Classics of Biology

By August Pi Suñer; Charles M. Stern | Go to book overview
Save to active project



THE forms assumed by living matter are countless, and vary, as we have seen, in both space and time. They are not identical at different places on the planet nor in different geological periods.

We have seen that each region of the earth, in the seas or on the land, has its own characteristic fauna and flora. The species living in any particular region are determined by a multitude of circumstances, for instance, humidity, temperature, particular foodstuffs available, and other co-existing and competing types of life, resulting in a balance between the various creatures which live contemporaneously or succeed one another. Thus it is that each country is characterized by its flora and fauna.

The areas of diffusion of the various species are also defined according to the circumstances obtaining in them. Plants generally show a more limited distribution, because it is impossible for them to move about. On the other hand, animals, being possessed of the power of movement, are able to wander to greater or less distances and spread. Even so, there are differences among the animals also, particularly observable in fossils, where we find deep-sea sedentary types or benthos living on the ocean bed more than a thousand fathoms down and usually showing themselves only in circumscribed areas which sometimes help us to define a particular geological facies or period of the earth's history. Wandering creatures, as for instance nekton and plankton, have a wider habitat.

Fortuitous chances of geography may impede or, on the contrary, foster the spreading of a species. Such particularly is the effect of mountains, streams and oceans. A species at a particular place tends to propagate itself, and the success or failure of its efforts will depend on its own special qualities, which include, for instance, greater or less incentive to live, adaptability, strength, reproductive powers, and so on, whilst on the other hand environmental conditions, be they avourable or adverse to the species, will also play their part. Among environmental conditions we must place foremost the possible


Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
Loading One moment ...
Project items
Cite this page

Cited page

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited page

Bookmark this page
Classics of Biology


Text size Smaller Larger
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

While we understand printed pages are helpful to our users, this limitation is necessary to help protect our publishers' copyrighted material and prevent its unlawful distribution. We are sorry for any inconvenience.
Full screen
/ 337

matching results for page

Cited passage

Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.

Are you sure you want to delete this highlight?