632 

tive of a genus which is frequently found attached to 
sand grains and shells by fistulose processes (Fig. 4). 
The. Globigerinae, to which we have already alluded, 
are often merely stages in the life-history of Orbulina 
universa, which we may break open and find in it the 
earlier Globigerina. 
Pulvinulina is represented by P. pauperata (Fig. 5). 
The object and significance of this variety of beau- 
tiful forms are entirely obscure, but have engaged the 
attention of many biologists both in the Foraminifera 
It must be remembered that 
Radiolarian, is 
and in the Radiolaria. 
a Foraminifer, like a a_ unicellular 

Fic. 4.—Polymorphina rotundata, d'Orbigny, fistulose and adherent. 
animal consisting solely of a microscopic globule of 
undifferentiated protoplasm, vivified by a nucleus the 
functions of which are little understood, but which are 
essential to the existence of the animal. 
This protoplasm is extended in the form of fine 
filaments which intermingle freely with one another, 
called pseudopodia, and their mechanical functions are 
locomotion and the capture of food. I have made a 
series of photographs of a fine Gromia which emerged 
from the mud in one of my tanks, climbed up the 
glass until it encountered a sea-weed stem, up which 
it crawled, and finally drew itself off on to the glass 
again by means of its pseudopodia. It then got lost, 


Pulvinulina pauperata, Parker and Jones. 
but on punching a hole in a piece of black paper 
which was then gummed on to the glass and a strong 
beam of light directed through it, it came back into 
the circle of light, apparently indicating that these 
creatures are sensitive to light. 
The other important function is the capture of food, 
which is caught outside the shell and usually drawn 
into it, as in this case of Miliolina durrandii, which 
has ingested a smaller Foraminifer and a diatom.*® 
89 Cf. F. Gamble in Ray Lankester, ‘‘ A Treatise on Zoology,” pt. i., fasc. 1, 
PP. 130, 127. 1900. 
36 E. Heron-Allen, ‘‘ Contributions towards the Study of the Bionomics of 
the Foraminifera,” Phil. Trans. Roy. Soc. (Lond.) 1915. 
NO. 2388, VOL. 95] 
NATURE 
[AUGUST 5, 1915 



It is a most significant, and at present unexplain- 
able, fact that these minute protoplasmic globules 
secrete such varied materials for the formation of their 
shells from the surrounding medium as carbonate of 
lime, silica, and even sulphate of strontium, but the 
nature and character of their protoplasmic bodies 
which perform this function defies analysis or defini- 
tion in the present state of our knowledge. 
Their life-cycles have been carefully studied by 
Lister,?7 Schaudinn,*® Winter,** and others, and the 
fact has been established that most, if not all, Fora- 
minifera exhibit the phenomenon called dimorphism 
(that is to say, they start with a large or a small 
central chamber), and that the small- ‘chambered (or 
microspheric) individuals reproduce themselves by 
means of amcebulz expelled from the shells producing 
the megalospheric young, whilst the large-chambered 
(or megalospheric) individuals discharge “flagellispores 
which conjugate with the flagellispores of other 
individuals and producing microspheric young, recom- 
mence or continue the life-cycle. 
Within the last few months, owing to the initiative 
and manipulative skill of Mr. J. E. Barnard, a new 
and very striking method of investigation has been 
developed which not only reveals the internal structure 
of Foraminifera without the need of cutting sections, 
and so destroying the specimens, but may have far- 
reaching results when applied to the study of the living 
protoplasmic bodies. This is the application of the 
X-rays to the shells, the results of which operation 
are highly interesting and significant.*° Here is a 
very thick and opaque species, Biloculina bulloides. 
The application of the X-rays reveals the internal 
arrangement of the chambers clearly. Here again is 
the coarse tropical calcareous form Opferculina com- 
planata, the whole of the interior septation of which is 
perfectly shown by the skiagraph. The process is 
especially valuable in connection with the arenaceous 
forms. Here is one of the most rugose species, and 
one which is exceedingly difficult to sectionise, owing 
to the sand-grains imbedded in the calcareous cement 
of which it is formed, Cyclammina cancellata. The 
skiagraph not only reveals its intricate labyrinthic 
interior, but here, as in the other species, reveals the 
fact that the individual is of the megalospheric stage 
of the life-cycle. The method is invaluable for the 
determination of doubtful species. The two species, 
Jaculella obtusa and Botellina labyrinthica, are exter- 
nally very difficult to distinguish, but the skiagraph 
reveals the simple tubular cavity of the former as con- 
trasted with the labyrinthic interior of the latter, and 
so determines the identity of the organisms. 
You may rightly ask yourselves in what, beyond the 
beauty of the shells, consists the interest and ‘value of 
the elaborate and concentrated study to which the 
Foraminifera have been subjected. Their value is both 
scientific and economic.’ They are the largest of the 
unicellular organisms—which are the closest to the 
beginnings of life—and if ever the structure and 
nature of protoplasm are to be determined, it will be, in 
my opinion, by the study of the Foraminifera that this 
conclusion will be arrived at. Economically they form 
the food of worms, starfishes, and many of the lower 
invertebrata, which in turn feed the food-fishes of the 
world. 


I come now to the concluding and most important 
section of my discourse, which concerns itself with the 
phenomena of purpose and intelligence which I have 
87 J. J. Lister, ‘Contributions to the Life-History of the Foraminifera,” 
Phil. Trans Rov. Soc, (Lond.), vol. clxxxvi. B, pp. 40'-453- 1805. 
38 F. Schaudinn, “ Die Fortpflanzung der Foraminiferen,” Wiegmann's 
Archiv, fiir Naturgeschichte, Jahrg. xlix., pp. 428- 454, 
39 OF, Winter, * Zur Kenntniss der Thalamophoren,” 
kunds, vol. vil. 1907. 
40 J. E. Barnard, “X-Rays in Relation to Microscopy,” Journ. R, Mier. 
Soc., p. 1. London, 1915. 
Archiv fiir Protisten- 
