. The British woodlice, being a monograph of the terrestrial isopod Crustacea occurring in the British Islands. Crustacea -- Great Britain; Oniscidae; Anthropoda; Invertebrates. THE BRITISH WOODLICE. reseryoir The openings are very difficult to identify, and Lereboullet (39, p. 113) was unable to find them. It is obvious that the openings must be underneath the plates that form the Q^^g pouch, and as a change of skin is required to set these free, it would appear that at ordinary seasons the ducts from the ovaries are closed. The writers have been able to determine from external examin- ation
. The British woodlice, being a monograph of the terrestrial isopod Crustacea occurring in the British Islands. Crustacea -- Great Britain; Oniscidae; Anthropoda; Invertebrates. THE BRITISH WOODLICE. reseryoir The openings are very difficult to identify, and Lereboullet (39, p. 113) was unable to find them. It is obvious that the openings must be underneath the plates that form the Q^^g pouch, and as a change of skin is required to set these free, it would appear that at ordinary seasons the ducts from the ovaries are closed. The writers have been able to determine from external examin- ation of specimens which had moulted and were about to lay eggs, that the oviducts at such time open to the inside of the base of each walking leg on the fifth segment. In similar specimens the oviducts were also follow- ed to the opening from bvoodpouch has already been described. The male organs con- sist of six testes arranged in two pairs,each of which is provided with a reservoir (see fig. 21), The efferent ducts from the two reser- voirs unite at the base of the thorax to form a com- mon duct (or" penis "). Development.—The eggs, in the common species of woodlice, at least, are laid at the beginning of summer, and are retained in the brood pouch, where they undergo their development. The process has been recently traced with great care by Professor Louis Roule (58) in Porcellio scaler and the description which follows is based upon his researches. As, practically speaking, the larval stages are passed within the egg, and there is no free embryo differing in form from the. Ciicd, 'S' 'Oidomiizal^ oppeTzdages FIG. 21.—THE MALE REPRODUCTORY ORGANS. (Oniscus asellus.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Webb, Wilfred Mark, 1868-; Sillem, Charles. London, Duckworth &a
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinverte, bookyear1906
