ANALYSIS OF THE LESSONS. xix 



673. Demodex folliculorum. 674. Description of its mouth. 675. Nutrimental 

 organs not yet found. 676. The itch : what causes it. 677. The Acarus scabicei. 

 678. Its mouth described. 679. The Spiders. 680. Nutrimental organs of the 

 domestic Spider. 681. Easy mode of finding the class of any articulate animal. 

 682. Characters of the Myriopods. 



LESSON XLIV. ORGANS OP NUTRITION IN THE TUNICATE MOLLUSCA, . p. 155. 



683. Nutrition predominates in the Mollusca. 684. Tunicata and other Mol- 

 luscs are headless. 685. The cause of their name. 686. The Brachiopods. 

 687. The Lamellibranchiata. 688. The Pteropoda. 689. The Gasteropoda. 

 690. The Cephalopoda. 691. Tunicata: how found: their tunic described. 

 692. Lining of the tunic : Cynthia pupa described. 693. The nutritive organs. 

 694. They are devoid of teeth, jaws, and salivary glands : possess a liver. 695. 

 Development of ovaria and oviducts. 696. The Pyrosoma described. 697. De- 

 scription continued. 



LESSON XLV. NUTRITION IN THE BRACHIOPODA, p. 157. 



698. The orders of the class enumerated. 699. Alimentary tube in Tere- 

 bratula; the arms described. 700. The nutrimental organs described. 701. 

 The same subject continued. 



LESSON XLYI. NUTRITION IN THE LAMELLIBRANCHIATA, AND IN THE 



PTEROPODA, p. 160. 



702. Organs of nutrition in the Oyster : its ovarium. 703. Development of 

 locomotive organs in Molluscous animals. 704. Form and position of them in 

 the Pteropods. 705. Some of them are provided with a shell. 706. Their size : 

 where found : they constitute the food of the Whale. 707. Hyalaea described. 

 708. Its nutrimental organs. 



LESSON XLVII. NUTRITION IN THE GASTEROPODS, AND IN THE CEPHA- 



LOPODS, p. 162. 



709. Position of the respiratory organs in certain Gasteropods. 710. Eolis 

 Inca. 711. Necessity for a higher grade of the nutrimental function. 712. Form 

 of the mouth in Aplysia faciata. 713. Its organs of nutrition. 714. The same 

 continued. 715. Number of gastric cavities : development of teeth. 716. The 

 teeth of Buccinum undatum: the tongue of the Limpet. 717. General de- 

 scription of the CEPHALOPODS. 718. The tongue and salivary glands. 719. 

 Alimentary canal described. 720. Description continued. 721. Description 

 concluded. 722. Apparently defenceless. 723. Desirable food for other ani- 

 mals. 724. The wisdom and beneficence of God displayed: their passive means 

 of defence. 725. Situation of the ink-bag. 726. "Indian Ink" and "Sepia," 

 how made. 727. Ink obtained from fossil Cuttle-fishes. 728. Their internal 

 skeleton. 729. Varied shape of the bone. 730. Its great lightness in Sepia 

 officinalis. 731. Microscopical exhibition of it. 732. The " blushing " of Cuttle- 

 fishes. 



