OF WASHINGTON. 95 



advanced system of classification. Insects and other small allied 

 animals are separated into the major groups on the basis of 

 metamorphosis, now for the first time suggested as means of 

 classification. The subclasses are based, for the most part, on 

 characters taken from the perfect insects. 



Four general classes are designated, as follows : 



Class I. Insects which emerge from the egg in, or nearly, their ultimate 

 forms, as spiders, snails, earthworms, leeches, lice, etc., with two sub 

 classes based on the habit of being oviparous or viviparous respectively. 



Class II. Insects which emerge from the egg with six feet and are active 

 throughout life, ultimately becoming winged, as locusts, dragon-flies, 

 ephemerids, earwigs, true bugs, etc., or practically insects having incom 

 plete metamorphosis. The ordinal groups in this section are not distin 

 guished. 



Class III. Insects with incomplete metamorphosis, or having distinctive 

 egg, larval, pupal, and imago states, with two subclasses, the one with 

 free limbs in the pupal state, as Coleoptera, most Hymenoptera, and some 

 flies, and the other, in which the limbs are not free, for the Lepidoptera. 



Class IV. Insects which do not shed the larval skin on completing larval 

 growth, but resume a condition, similar to an egg, in which the skin of 

 the mature larva serves as a sort of cocoon, as most Diptera (flesh-flies, 

 etc.). 



In the case of this last section, Swammerclam recognized that 

 a true chrysalis is found ultimately with the old larval envelope 

 corresponding with that of class III, but nevertheless he con 

 sidered the character described a good one, and with less reason, 

 on the authority of Reaumur, who strongly criticised him, he 

 made his class IV include generally all worms living in caterpillars 

 (parasites) and in fruits, galls, and rotting wood. 



As an influence on zoological science in general, John Ray is 

 perhaps the most important name of the period, though owing 

 very much in the department of insects to Swammerdam. Ray 

 was born in 1628 and died somewhere between 1704 and 1707. 

 He was an English theologian, and was one of the first of the 

 new school of naturalists to methodize his knowledge of the ani 

 mal kingdom, being with Swammerdam the forerunner and 

 principal guide of Linne in this department of natural science. 

 His chief writings are " Wisdom of God Manifested in the 

 Works of Creation" London, 1691, and "Historia Insec- 

 torum" 1700. In the preparation of the last he was much as- 



