ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ■>'!! 



a duct lined with chitin, and the large constituent cell of each appears 

 to lie deeper than the hypodermis. In addition, other unicellular glands 

 occur in connection with the tracheae, into whose lumen they open. 

 Further, a pair of compound tubular glands was found in the last 

 abdominal segment, which open to the exterior, and appear to be typical 

 Gilson's glands. The function of all these glands remains uncertain. 



Scale Insects. — Miss R. W. Patterson * has studied the life-history 

 of the three known species of the genus Cerococcus, which occur on 

 Californian oaks. One of the species — Cerococcus ehrhorni — occurs in 

 apparent symbiosis with a white fungus, which appears to live on the 

 honey-dew formed by the scale. In this species only a thin waxen case 

 is formed, but C. quercus secretes a large amount of bright yellow wax 

 •\hich forms a case surrounding the insect. The eggs are laid within 

 the case, the body of the female shrinking greatly afterwards, so that the 

 lumen of the case is filled up with the eggs. 



S. I. Kunwana j describes three new species of Californian Coccids 

 belonging to the genus Eriococcus, and also notes the discovery in 

 California of Pseudolecanium tokionis Ckll., a coccid first found in 

 Tokyo, Japan. 



Mr. G. A. Coleman J describes as Dactylopius sequoise sp. n., a scale 

 found by him on the redwood (Sequoia sempcrvirens) near Stanford 

 University. Both sexes were found, and the life-history was followed 

 from the egg. The male has well-developed wings, but no attempt at 

 flight was observed. 



Skinkai Inokichi Kunwana § has visited all the main islands of 

 Japan, except Shikoku, in order to study the distribution and natural 

 enemies of the San Jose scale (Aspidiotus perniciosus). Prof. Vernon L. 

 Kellogg, who writes a preface to his report, is of opinion that Kuwana's 

 results tend to settle in the affirmative the disputed question as to 

 whether Japan is or is not the home of this destructive insect ; but it 

 is to be noted that the scale was in no instance found upon a wild tree. 

 The scale is very widely distributed in Japan, but except in a few places 

 is not abundant enough to endanger the orchards. It seems to have 

 several insect enemies, especially an Aphelinid fly and one of the 

 Coccinellidae. The weight of Japanese opinion would seem to incline 

 against the view that it is a native species, and it is believed by Japanese 

 gardeners to be more destructive to foreign than to native trees. 



o 



Defensive or Odoriferous Glands of Cockroach.|| — L. Bordas finds 

 on the postero-abdominal region of the males of Periplaneta orientalis 

 ;md P. americana a large compound arborescent gland, resting on the 

 ventral wall. It is formed of a series of ramifying dichotomising tubes, 

 which some observers have connected with the genital apparatus. There 

 is no reservoir, but the duct opens by an oval orifice below the penial 

 tube. The secretion is a volatile alkaline liquid, of strong odour, 

 suggesting mice or decomposing cheese. Although the secretion is 



* Contributions from the Hopkins Laboratory of the Leland Stanford Jun. 

 University, xxv. (1901) pp. 387-98 (3 pis.). 



t Tom. cit., pp. 399-408 (2 pis.). J Tom. cit., pp. 409-20 (1 pi.). 



§ Tom. cit.. pp. 1-14 (I fig.). || Comptes Rendus, exxxii. (1901) pp. 1352-4. 



