Since the Hathi Trust text version of these pages in the Britanica article was garbled — words and partial sentences from the left column mixed with the right and vice versa — I have used ABBYY OCR (optical character recognition) software to create the following transcription. In addition, I have added paragraphing far easy reading and added a cropped map from another edition of the Britanica. George P. Landow
y opening up a paasage by which the faunal forms of the Red Sea and of the Mediterranean may respectively advance north and south into regions from which they have hitherto been excluded, the canal has produced some curious results, which have been lately investigated by Dr. Conrad Keller of Zurich (“Fauna im Suez-Kanal u. Diffusion de Mediter. u. Eryth. Thierwelt,” in Neue Denkschriften d. allg, schweizer Ges. f. Naturwiss., Zurich, 1883). Deep-sea forms are, of course, prevented passing by the shallowness of the canal; and the sandy nature of the soil, the large lakes, the currents, the disturbing influence exerted by the continual movement of vessels, and the excessive saltness of the water all tend to limit and retard the progress of even those forms most adapted to make their way through such a channel.
The salinity of the water is much greater than that of the Mediterranean or the Red Sea. This is due mainly to two causes,—the rapid evaporation to which the water in the canal is subjected and the gradual melting of the deposits of salt (the result of previous evaporation in distant ages in some of the depressions through which the canal is carried. In the Bitter Lakes, for example, it was found in 1872 that on an average each cubic metre of water contained 156.42 lb of salt, or about three times as much as ordinary sea water. A certain number of forms common to the Red Sea and the Mediterranean appear to have migrated from their original homes when in Quaternary times the isthmus was still a lagoon. These being discounted, the following remain as the result of the recent connection established between the seas:
(1) from the Mediterranean Pholas Candida (as far as Ismailia), Solen vagina, Sphieroma serrata (to the south of Timsah Lake), Cardinal edule, Gammarus sp. (to the nearer end of the. Great Bitter Lake), Solea vulgaris, Umbrina cirrhosa, Ascidia intestinalis, and Labrax lupus (to the Red Sea);
(2) from the Red Sea seventeen forms were found journeying, but one only, Mytilus variabilis, had got out into the Mediterranean proper; Ostracion cubicus and Caranx macrophthalmusm had just got en route, and Pristipoma stridens, the curious fish that utters a cry when caught), Mactra olorina and Cerithium scabridum were found in Lake Menzaleh. This lake seems to prove in the meantime an obstacle to the passage of eight other species. [22.653]
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Bibliography
“Egypt.” The Encylopædia Britanica or Dictionary of Arts, Sciences, and General Literature. Philadelphia: Maxwell Sommervile: 1881. 25 vols. Hathi Trust Digital Library online version of a copy in the University of Illinois Urbana-Champaigne Library. Web. 18 August 2020.
Last modified 18 August 2020