354 



KNOWLEDGE. 



September, 1913 



changed in the metamorphosis, but there is not much difference 

 between pupa and moth. There is no loss of nitrogen in 

 gaseous form during the metamorphosis. During the pupal 

 and moth stages the greater part of the fat accumulated by the 

 silkworm is consumed. In the pupal and moth stages the 

 waste of body protein is repaired with amino-acids, and a 

 part of the latter is further transformed into ammonia. 

 Splitting of the protein in the silkworm is caused by the action 

 of some proteolytic enzyme. 



GEOGRAPHICAL DISTRIBUTION OF BED-BUGS.— 



The family of bugs known as Cimicidae is nowadays repre- 

 sented all over the world — seven species in Europe, six in 

 Africa, five in Asia, two in Australia, and seven in America. 

 The two Australian species are importations by man, and the 

 same two have been introduced into America. Dr. G. 

 Horvath, of Budapest, has been recently looking into the 

 matter, and finds reason to believe that the common bed-bug 

 (Cimex lectularius) is indigenous in the Mediterranean region, 

 whence it has spread everywhere. The other bed-bug in the 

 strict sense is Cimex hemipterus, a native of tropical regions 

 of Africa and Asia, whence it also has been transported to 

 various parts of the world, such as the Antilles and Brazil. 

 Dr. Horvath thinks that both species of bed-bugs were, like 

 most of their fellow-species, parasites of bats to begin with, 

 and that they shifted their attention from bats to man. 



A MARINE BUG. — In 1878 Baron Bonnaire discovered a 

 marine Hemipteron, Aepophilus bonnairei, which lives 

 under deeply imbedded stones at low tide. It can live for 

 days under water — indeed, it often occurs at levels which are 

 not uncovered except at very low tides. It also occurs higher 

 up in the Fucus zone. More information in regard to its 



distribution has been recently collected by R. Lienhardt, who 

 points out that the insect probably gets into crevices with 

 imprisoned air. More than one naturalist has found it on the 

 back of a starfish and among worm-tubes and the like. 

 There are records of its occurrence from Cornwall, the 

 Channel Islands, Wimereux, Tatihou, Roscoff, Concarneau, 

 He de Re (where it was first found), and from Galicia. 



FORAMINIFERA AS WORLD-BUILDERS. — From 

 Cambrian times or even earlier the shells of Foraminifera 

 have contributed notably to the crust of the earth. Messrs. 

 Heron-Allen and Earland have contrasted the contributions 

 made in different geological ages. Thus there is but a single 

 record of Foraminifera for the Devonian, while in the 

 Carboniferous they began to form enormous deposits. There 

 were many forms in the Cretaceous, but they did not form the 

 great deposits characteristic of the Foraminiferal Golden Age 

 in the beginning of the Tertiary times. Nowadays, as everyone 

 knows, a few pelagic genera are building up great deposits of 

 Globigerina ooze on the floor of the deep sea. In regard to 

 the beds of chalk ranging from the Chalk Marl to the Upper 

 Chalk, the authors make a useful note : " It is one of those 

 popular beliefs which die so hard that chalk is made up 

 entirely of the shells of the Foraminifera, and the textbooks 

 and microscopical works abound with statements to that 

 effect. . . . The so-called ' spheres ' of the chalk are perhaps 

 the origin of the belief that chalk is built up of the shells of 

 Foraminifera. But, whatever the ' spheres ' may be, we are 

 convinced that they are not Foraminifera." They may be 

 the firm tests of Infusorians. There are, indeed, plenty of 

 Foraminifera in many zones of the Chalk, but in most cases 

 their number is small compared with the whole bulk of 

 amorphous matter. 



A HYDROID EPIZOIC ON A PARASITIC COPEPOD 



At the Portsmouth Meeting of the British Association, held in 

 1911, Professor Hector Jungersen, of Copenhagen University, 

 read a paper on a new Gymnoblastic Hydroid (Ichthyocodium 

 sarcotretis) epizoic on a new Parasitic Copepod (Sarcotretis 

 scopeli) infesting Scopelus glacialis Ros. 



Professor Jungersen very kindly allowed us to copy the 

 lantern slides which he exhibited at the time, and these are 

 now reproduced on page 352 to illustrate his interesting 

 description, which is as follows : — 



The Hydroid coats more or less of the external part of a 

 parasitic Copepod deeply sunk into the body of Scopelus 

 glacialis (see Figure 384, page 352). It consists of : — 



(1) Polypes, devoid of tentacles and growing from a 

 network of delicate tubes in a basal membrane without 

 perisarc ; and : — 



(2) Medusae-buds, arising from the base of the polypes. 

 The largest buds possess a bell with two marginal tentacles, 

 four simple radial canals and a manubrium. When fully 

 developed they are set free as Medusae (Anthomedusae). This 

 new Hydroid, Ichthyocodium sarcotretis (see Figure 387), 

 is related to Hydrichthys minis Fewkes, epizoic on the fish 

 Seriola zonata. With the Hydrichthys it has to be 

 adopted into the family of Corynidae, as defined by Stechow 

 (1909). The Parasitic Copepod, Sarcotretis scopeli (see 

 Figure 385), represents a new genus and species of the family 

 Lernaeidae, allied to genera like Peroderma, Lernaeenicus, 

 Lernaea and Pennella. 



The adult female has an elongated body, the middle part of 

 the long genital segment constricted into a narrow, firmly 

 chitinized stalk ; only the distal claviform part behind the 

 stalk protrudes outside the host. Cephalothorax with dorsal 



shield fully preserved; two large clumsy outgrowths arise 

 below the margins of the shield, but no other outgrowths are 

 present. No eyes are visible. Antennules are linear, 

 antennae cheliform, the sipho large ; only one pair of 

 maxillipeds ; three pairs of abdominal feet, the two anterior 

 biramous, the posterior with a single ramus ; three free 

 abdominal segments with terga and sterna well developed. 

 It is found in the eastern part of the Atlantic, inserted into 

 the body of Scopelus glacialis, the body wall of which it 

 pierces, penetrating to the alimentary tract. 



A series of Metamorphosis-stages has been found on the 

 same species of fish, namely, 



(1) A Cyclops-stage (see Figure 388) resembling that of 

 Lernaea branchialis and capable of moving along on its 

 host and of attaching itself by means of its strong cheliform 

 antennae. 



(2) Four Pupal-stages (see Figures 388 and 386) passively 

 fixed to their host by means of a hardened secretion from the 

 rostrum. Inside the last Pupa the copulatory form has been 

 observed. After impregnation the female takes up parasitic 

 life anew, but in a more intense form ; it pierces the skin of 

 Scopelus glacialis, and, gradually growing, it penetrates 

 through the muscles and reaches by and by the intestines of 

 the host. 



The triple association between the Fish, the Copepod, and 

 the Hydroid seems to be a regular one: of fourteen adult 

 Sarcotretes seven carry the Ichthyocodium ; and the loss 

 of tentacles in the Polypes of the latter seems to show that 

 the Hydroid in some way or other depends on the Fish for 

 getting its food. 



