FORAMLNTFERA AND RADIOLARIA. 10T 



it presents in existing Foraminifera, it must be accounted a Mineral infiltration. 

 To this the Author would reply: (1) That a prolonged and careful study of this 

 'canal-system,' in a great variety of modes, with an amount of material at his 

 disposal many times greater than Prof. Mobius could command, has satisfied him 

 that in well-preserved specimens the canal-system, so far from being vague and 

 indefinite, has a very regular plan of distribution; (2) That this plan does not 

 differ more from the arrangements characteristic of the several types of existing 

 Foraminifera, than those differ from each other,. its general conformity to them 

 being such as to satisfy Prof. Max Schultze (one of the ablest Foraminiferalists 

 of his time) of its Foraminiferal character; and (3) that not only does the distri- 

 bution of the canal-system of Eozoon differ in certain essential features from 

 every form of Mineral infiltration hitherto brought to light, but that canal-sys- 

 tems in no respect differing from each other in distribution are occupied by dif- 

 ferent minerals, a fact which seems conclusively to point to their pre-existence 

 in the Calcareous layers, and the subsequent penetration of these minerals into 

 the passages previous occupied by sarcode, precisely as has happened in those 

 * internal casts ' of existing Foraminifera ( 497) which Prof. Mobius altogether 

 ignores. 



The argument for the Foraminiferal nature of Eozoon is essentially a cumula- 

 tive one, resting on a number of independent probabilities, no one of which, taken 

 separately, has the cogency of & proof ; yet the accordance of them all with that 

 hypothesis has an almost demonstrative value, no other hypothesis accounting at 

 once for the whole assemblage of facts. As it is the Author's intention to set 

 forth this in the best and completest form he can devise, at the earliest possible 

 period, he would beg for a suspension of judgment on the part of those who have 

 credited Prof. Mobius with having completely settled the question; the small 

 amount of evidence contained in his Memoir bearing no comparison to that of an 

 opposite bearing of which the Author is in possession. 



498. Collection and Selection of Foraminifera. Many of the Forami- 

 nifera attach themselves in the living state to Sea -weeds, Zoophytes, etc. ;. 

 and they should, therefore, be carefully looked-for on such bodies, espe- 

 cially when it is desired to observe their internal organization and their 

 habits of life. They are often to be collected in much larger numbers, 

 however, from the sand or mud dredged-up from the sea-bottom, or even 

 from that taken from between the tide-marks. In a paper containing 

 some valuable hints on this subject, 1 Mr. Legg mentions that, in walking 

 over the Small-mouth Sand, which is situated on the north-side of Port- 

 land Bay, he observed the sand to be distinctly marked with white 

 ridges, many yards in length, running parallel with the edge of the 

 water; and upon examining portions of these, he found Foraminifera in 

 considerable abundance. One of the most fertile sources of supply that 

 our own coasts afford, is the ooze of the Oyster-beds, in which large- 

 numbers of living specimens will be found; the variety of specific forms, 

 however, is usually not very great. In separating these bodies from the 

 particles of sand, mud, etc., with which they are mixed, various methods 

 may be adopted, in order to shorten the tedious labor of picking them 

 out, one by one, under the Simple Microscope; and the choice to be 

 made among these will mainly depend upon the condition of the Foram- 

 inifera, the importance (or otherwise) of obtaining them alive, and the 

 nature of the substances with which they are mingled. -"Thus, if it be 

 desired to obtain living specimens from the oyster-ooze, for the examina- 

 tion of their soft parts, or for preservation in an Aquarium, much 

 time will be saved by stirring the mud (which should be taken from the 

 surface only of the deposit) in a jar with water, and then allowing it to- 

 stand for a few moments; for the finer particles will remain diffused 

 though the liquid, while the coarser will subside; and as the Forami- 

 nifera (in the present case) will be among the heavier, they will be found 



1 " Transaction of Microscopical Society," 2d Series, Vol. ii. (1854), p. 19. 



