APLYSIA. 189 



Rang, Milne Edwards, Spengel, Blochmann, Cunningham, 

 Vayssiere, Lacaze Duthiers, Mazzarelli, Guiart, and Blatin. 

 Very little work has been done in this country ; nearly all 

 these authors investigated the larger Mediterranean species. 

 Milne Edwards (1847) and Blatin and Vies (1906) contributed 

 to our knowledge of the circulation, Cunningham (1883) worked 

 out the relations of the kidney and the pericardium, to Spengel 

 (1881), Lacaze Duthiers (1888), and Guiart (1901) we owe a 

 comprehensive account of the nervous system, and Mazzarelli's 

 important monograph, published in 1893, has already been 

 noticed. 



The first observations on the development of Aplysia 

 were due to van Beneden, who, in 1841, described the veliger 

 larva* with its nautiloid shell. In 1874, Lankester published 

 a paper on the development of Aplysia, and eight years 

 later Manfredi summarised the information on the subject. 

 Blochmann also worked on the embryology. MazzarelU 

 published several papers on the development, and corrected 

 Lacaze Duthier's curious mistake in supposing the primitive 

 kidney to be an anal eye. More recently, Georgevitch (1900) and 

 Carazzi (1900) studied the embryology, and the latter, in 1905, 

 worked out the cell lineage in the early stages. Carr Saunders 

 and Margaret Poole, in 1910, made a careful investigation of 

 the work of previous authors. The metamorphosis of the larva 

 into the adult condition is not yet known. 



The large size of the Mediterranean species of Aplysia has 

 made them suitable for histological and physiological study. 

 The histology of the mantle glands was investigated by 

 Blochmann in 1883 ; in 1888, Robert studied the microscopic 

 structure of the hermaphrodite gland; and Cuenot, in 1890, 

 described the blood and lymphatic glands. Mazzarelli has 

 written several papers on the histology and physiology of 

 Aplysia, the chief being on the reproductive system and the 



* Sars, however, had discovered this larva. 



