13 
containing cell elements and sarcode, and surrounded by a layer of sareode, 
giving off pseudopodia, which commonly stand out like rays, but may, and 
do, run into one another, and so form networks. 
The fourth type of structure is probably furnished by those anomalous 
creatures, the Acinetse ; the radiating processes of which serve as suctoria 
tubes, down which the juices of their prey are conveyed. 
On the question of the causal connection between life and organization 
introduced by Huxley in his prefatory remarks, I shall, if time admit, say 
a few words after we have become acquainted with the new species of land 
Amoebae described by Dr. Greef . Suffice it here to say, that without straining 
the terms of Huxley's own definition of Amoebse, organizations of a very 
definite kind may be claimed for animals which possess a nucleus and con- 
tractile vesicle, and present an approach to a sexual mode of reproduction, 
besides multiplication by division of substance. 
In his Hunterian Lectures (1868), Huxley specially mentions the nucleus 
and contractile vesicle of Amoebae, their multiplication by fissure, and by a 
low form of sexual reproduction. The Amoeboid stage of the Gregarinida, 
ending in an encysted condition, in which reproduction by pseudonaviculae, 
is also maintained by Huxley. The observations of Greef considerably 
augment our knowledge of structural changes, and of the mode of reproduction 
of the Amoebae, and tend, as I think, to modify the broad assertion that these 
animals have no organization in the strict sense of the word. 
To Dr. Greef's account I shall now direct your attention. 
And first, in respect to their habitat and mode of life. Dr. Greef finds 
these animals very commonly present in sand, and at the root fibres of mosses, 
grasses, and other plants which grow in shallow mass upon stones, rocks, 
walls, house roofs, trees, &c, that is, upon a firm bottom. They appear, 
therefore, in exactly the same places as the Arctiscoidee, wheel animalcules, 
anguillulinae, &c, e. g. in the sand under thin liverworts and lichens, and 
are found generally in company with these, — may therefore be sought for 
wherever these creatures are found. Dr. G. however has often searched for 
them in vain where the above mentioned animals exist in abundance, while 
at other times a numerous population of Amoebae is to be seen under every 
moss examined. The conditions favorable to their presence Dr. G. has not 
been able to determine with accuracy, but considers that a position exposed 
to the sun, and the greater or less abundance in the earth of small diatomacese 
and other algae, which naturally constitute their chief aliment, must materially 
influence their presence. As to their condition of life, these Amoebae, living 
generally in company with Arctiscoidaa, must share in common with them 
the power of withstanding a high degree of dryness for a long time. Tho 
