148 W. A. KIDD, ESQ., M.D., B.S., M.B.C.8., F.Z.8-. ON 
and enters considerably into the protecting structure of 
lower animals. In the tiny foraminifera, which show an 
advance upon amoebee, there is, as a rule, a shell or “ test” 
perforated by minute protusions of the body-substance, 
whence their name. These “tests” are of great variety 
and beauty, as, for example, in the nautiloid foraminifera, 
with their microscopic shell fashioned like that of the higher 
pearly nautilus. Among this order are found the beautiful 
and ancient nummulites, honoured of old by entermg imto 
the “nummulite” limestone of the Egyptian Pyramids, with 
their small coin-shaped shells. We must not forget to 
notice the minute Globigerina, which go to make up with 
their myriad skeletons the Chalk formations of the world. 
The Radiolaria are another great division of the Protozoa, 
full of forms of beauty with varied contrivances for the 
protection of their bodies. Professor Haeckel was occupied 
for teu years in the study of the Radiolaria, brought to hght 
by the Challenger Expedition, and has identified 3,500 
species. The Polycystine also, which have contributed to 
form the flint all the world over, have “skeletons” of 
extreme beauty and variety, though microscopic in size. 
For example, one Radiolarian called Ziphacantha Murrayana 
(after Dr. Murray of the Challenger Expedition) possesses 
a more elaborate skeleton, passing through the body of the 
animal, consisting of delicate spicules arranged in a radiate 
form, with secondary connections, in most exact geometrical 
order. 
The next division in the scale of animal life among the 
Zoophytes or Coelenterates is that of the sponges. At this 
stage the one-celled animals are passed by, and tissues and 
organs begin to be seen. The soft body-substance of the 
sponges is supported and protected by a framework of flinty, 
horny material. Some sponges exist in fresh water, but most 
of them in sea-water ; some are calcareous in their skeletons, 
others siliceous. We should not forget how valuable a 
secondary purpose for the comfort of us human beings are the 
skeletons of the horny sponges found in the Mediterranean 
and West Indian Islands, and their beautiful elasticity and 
firmness. It is not necessary, because the primary purpose of 
these skeletons of sponges is the protection of the individual, 
to forget the secondary uses and purposes to which they are 
applicable. 
Of all the sponges the famous Venus’s Flower Basket, or 
Euplectella, is the most beautiful, and serves as a model of 
