ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 315 



tube formed by the " genital wings " of a very large species of Balano- 

 r/lossus from the Gulf of California. One of the Polynoids bore fixed 

 to its back a remarkable Stomatopod, also new, belonging to the genus 

 Lysiosquilla ; its dorsal surface has a marked mimetic resemblance to 

 the back of the Polynoid. In 1882 Giard reported the occurrence of 

 •another Polyehret, Auoplonereis (Opliiodionnus) herrmamii, as a com- 

 mensal on two species of Balanoglossus. 



Anatomy and Histology of Blood Vessels in Lumbricus.* — 0. 

 Gungl has investigated this subject. A typical vessel possesses a homo- 

 geneous connective tissue membrane, sharply defined and deeply stained 

 by rubin and acid-fuchsin. Towards the lumen are elongated cells 

 which never form an epithelial-like lining. On the outer side the wall 

 cells lie upon the intima, and from these arise the striped muscle fibres 

 which are arranged within the connective tissue in a doubly oblique 

 manner. If the vessel is free in the body cavity, e.g. ventral vessel, it 

 possesses a peritoneal layer. The small vessels and capillaries are 

 derivable by loss of musculature from a vessel of the ventral type. 

 The author further works out a comparison between these and the 

 capillaries of Vertebrates. 



Variation and Correlation in the Earthworm.t — Raymond Pearl 

 and W. 1ST. Fuller have made statistical studies of Lumbricus agricola 

 from which they conclude that there is a great range of variation in 

 the total number of somites (79-1G4) and a rather high variability as 

 measured by the standard deviation and the co-efficient of variation. 

 This earthworm is markedly more variable in length than in the number 

 of somites. The clitellum is decidedly more variable with respect to the 

 number of its somites than is the body in front of the clitellum. As the 

 number of somites in front of the clitellum increases, there is a strongly 

 marked tendency for the number of clitellar somites to decrease. With 

 regard to negative correlation, the suggestion is made that it may have 

 ultimately the same physiological basis as compensatory regulation. The 

 foregoing are the main points in the abstract ; the complete paper has 

 has not yet appeared. 



Gephyrea of Japan.} — Iwaji Ikeda gives an account of 87 species — 

 26 Sipunculoids under 7 genera and 11 Echiuroids under 3 genera. 

 Previous to this paper onlyfour Gephyreans seem to have been recorded 

 from Japan. Of the o7 species described, 24 are new. A useful dia- 

 gnostic key is given. 



Ovogenesis of Sagitta.!— N. M. Stevens supplies the following 

 ■additional facts regarding the ovogenesis in Sagitta, determined on 

 material of 8. eleyans. The so-called sperm-oviduct of Sagitta is 

 merely a sperm-duct. A temporary oviduct is formed periodically be- 

 tween the sperm-duct and the germinal epithelium. This duct appears 

 to be opened up by the activity of the individual eggs pushing their 

 way out of the ovary proper and in between the germinal epithelium 



* Arbeit. Zool. Inst. Wien, xv. (1904) pp. 155-82 (1 pi.). 

 t Fifth Report Michigan Acad. Sci., 1903, pp. 200-2. 

 % Journ. Coll. Sci.. Tokyo, xx., Art. 4 (1904) pp. 1-87 (4 pis.). 

 § Zool. Jahrb., xxi. (1901) pp. 243-52 (1 pi.). 



