306 



MESSES. C. SHEARER, W. DE MORGAN, AND H. M. FUCHS 



with regard to the development of the posterior ciUated epaulettes. Four 

 individuals developed both posterior epaulettes (Plate 2"2, fig. 74). Eight had an 

 epaulette on one side of the body only (Plate 22, fig. 75), and eleven completely 

 lacked the epaulettes (Plate 22, fig. 76). Thus, with regard to the green pigment, 

 these larvae were maternal, as in all experiments of 1912 and of previous years ; but 

 with regard to the posterior ciliated epaulettes, some were maternal, some paternal, 

 and others of a mixed form. This is shown diagrammatically in text-fig. 11. 



pcilcp 



Text-fig. 11. — Diagram to show the three types of hybrid larvae produced in a certain cross of 

 E. esculentus ^ y. E. miliaris $ made in 1912. y.cil.ep., posterior ciliated epaulette. 



2. E. miliaris % X E. esc i dent us $ — 



In 1912 it was very difficult to fertilize E. miliaris eggs with sperm of another 

 species, whether E. esctdenUts or E. acutus, although the eggs appeared to be 

 perfectly ripe. In previous years crosses with E. miliaris female had not been 

 so easy to make as with E. esculentus or E. acutus females, but in 1912 seldom 

 more than 20 per cent, of the eggs segmented and formed larvae. Nevertheless, 

 the resulting plutei were perfectly normal and healthy. This difficulty was not 

 experienced in making crosses with E. esculeutus or E. acutus eggs, in which 

 cases, as in former years, 80 per cent, or 90 per cent, of the eggs usually developed. 



Wit/i tivo exceptions, oil the cultures made from fertilizations of E. miliaris eggs 

 with E. esculentus sperm gave larvce with a j^citerncd inheritance, which was exactly 

 the op)posite of the condition in 1909-11. In general form the larvae Avere of 

 the E. esculentus type. They developed the posterior ciliated epaulettes and lacked 

 the green pigment (Plate 22, fig. 77). 



The exceptions were as follows : — • 



One resembled the exceptional case just described in the cross E. esculentus ? 

 X E. miliaris $ . The larvae were of the E. esctdentvs form. All had the paternal 

 absence of green pigment, but they diftered among themselves with regard to the 

 development of the posterior epaulettes. Eighteen had both posterior epaulettes, 

 five had an epaulette on one side of the body only, and nine had neither posterior 

 epaulette. 



