Toyama, On certain characteristics of the Silk-worm etc. 595 



3. Blue worms. In Japanese or Chinese breeds, we often 

 found certain blue worms, characterized by the special blue colour 

 of the skin, its cause being the absence of special pigments in the 

 hypodermal cells. This is also a Mendelian characteristic and 

 recessive to the normal-skinned characteristic. 



4. "Knobbed" or "Dragon-horned" worms. In the larvae 

 of certain Chinese breeds called "Dragon-horned", the worm has a 

 pair of small knobs or horns on the dorsal part of certain segments. 

 These knobs are only an evagination of hypodermal epithelium 

 together with the cuticle, and are generally found on the second, 

 third, fifth and eighth, sometimes on the sixth or seventh, and 

 more rarely on the other segments. This is also a Mendelian 

 characteristic dominant to the normal one. Quajat's 3 ) results are 

 quite in accordance with ours. 



5. Spotted worms. These are characterized by the presence 

 of a pair of large yellowish brown or greenish brown spots on 

 the dorsal part of certain segments of the worm. As to their 

 number, it varies greatly according to the individual. Thus certain 

 worms have the pair of spots in every segment except the anal 

 segment, while some others bear a pair of the spots on the fifth 

 and eighth segments. Normally they are provided with the spots 

 on the 5th, 7th, 8th and 9th. This is also a Mendelian charac- 

 teristic, dominant to the absence of this characteristic. 



6. Striped characteristic. Worms who are decorated with 

 these markings are called striped or zebra worms. They are found 

 in breeds reared in Japan, China, India, Siam, Korea, Europe or 

 Turkey. This is also a Mendelian characteristic, dominant to the 

 non-striped characteristic. 



7. The red and dark worms 4 ). In normal breeds, the worms 

 in the first larval stage are brownish black, but now and then we 

 find orange-red worms whose larval markings in advanced stages 

 are reddish brown, contrary to the normal dark or brownish black 

 colour. This is a Mendelian characteristic recessive to the normal 

 dark. 



8. Moricaud or "bear" worms. These are found in certain 

 European, Turkish, Japanese, Chinese or tropical breeds. 



9. Chinese black worms, characterized by the dark marking? 

 which cover all the dorsal part of the larval body except the inter 

 segmental region, where it is white, and consequently it looks like 

 a black worm striped with white rings. 



10. Normal patterned worms. These are generally found 

 in nearly every breed. The ground colour of the body is nearly 

 white, marked with fine spots or faint markings. Conspicuous 



3) Quajat-Gulla reproduzione degli incroci. 1911. 



4) Toy a ma, K. - - A sport of the silk-worm and its hereditary behaviour. 1909. 



39* 



