264 LAWSON, ON HELIX ASPEKSA AND HORTENSIS. 



matter may be deposited around granules, layer after layer, 

 until a mass of considerable size is produced ; or a material 

 allied to starch, and formed from the same germinal matter 

 as this substance, may be deposited upon the inner surface of 

 the investing membrane (cell-wall) of an elementary part in 

 thin laminae. 



There is every reason to believe that in this case of cancer 

 of the liver the cell- containing network of the lobules had 

 been encroached upon by the cancerous growth, growing 

 principally in the interlobular fissures. The excreting chan- 

 nels which carry off the bile would soon become occluded, 

 and the distribution of blood to the substance of the lobule 

 much diminished. Nevertheless, some of the masses of ger- 

 minal matter of the original elementary parts still retained 

 their vitality, as was proved by their being coloured by the 

 carmine ; and a certain amount of formed material under 

 these disadvantageous circumstances was produced. We may 

 assume that this, being placed under very adverse conditions, 

 did not undergo precisely the same changes which occur in 

 the normal state ; and, amongst other substances resulting 

 from tlie changes induced, was this starchy matter, which 

 was prevented from escaping, and was slowly deposited in 

 the insoluble form, the amyloid masses gradually increasing 

 in size by deposition on their exterior. 



On the Generative System of Helix ASPERSA-awrf 

 HORTENSIS. By Henry Lawson, M.D. 



(E-ead before the Natural History Society of Dublin, December, 1860.) 



The following observations upon the reproductive system 

 of Helix aspersa, our commonest Irish snail, are given as the 

 result of a series of dissections and microscopic examinations, 

 made during the past summer. The object of the paper is 

 twofold — first, to supply a deficiency in our text-books on 

 zoology and comparative physiology, by publishing the de- 

 scriptive anatomy of the species of Helix most widely dis- 

 tributed in Ireland, and of thus affording to the student of 

 natural history an opportunity of verifying by dissection the 

 descriptions given — a circumstance too much neglected by 

 writers upon the subject, who prefer the less difficult task of 

 quoting, wholesale, the investigations of Cuvier, which were 

 made upon that species [Helix pomatia) most abundant in 



